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Sample records for baseline xfel undulator

  1. Scheme for Generation highly monochromatic X-Rays from a baseline XFEL undulator

    International Nuclear Information System (INIS)

    One goal of XFEL facilities is the production of narrow bandwidth X-ray radiation. The self-seeding scheme was proposed to obtain a bandwidth narrower than that achievable with conventional X-ray SASE FELs. A self-seeded FEL is composed of two undulators separated by a monochromator and an electron beam bypass that must compensate for the path delay of X-rays in the monochromator. This leads to a long bypass, with a length in the order of 40-60 m, which requires modifications of the baseline undulator configuration. As an attempt to get around this obstacle, together with a study of the self-seeding scheme for the European XFEL, here we propose a novel technique based on a pulse doubler concept. Using a crystal monochromator installed within a short magnetic chicane in the baseline undulator, it is possible to decrease the bandwidth of the radiation well beyond the XFEL design down to 10-5. The magnetic chicane can be installed without any perturbation of the XFEL focusing structure, and does not interfere with the baseline mode of operation. We present a feasibility study and we make exemplifications with the parameters of the SASE2 line of the European XFEL. (orig.)

  2. The Full Potential of the Baseline SASE Undulators of the European XFEL

    CERN Document Server

    Agapov, Ilya; Feng, Guangyao; Kocharyan, Vitali; Saldin, Evgeni; Serkez, Svitozar; Zagorodnov, Igor

    2014-01-01

    The output SASE characteristics of the baseline European XFEL, recently used in the TDRs of scientific instruments and X-ray optics, have been previously optimized assuming uniform undulators without considering the potential of undulator tapering in the SASE regime. Here we demonstrate that the performance of European XFEL sources can be significantly improved without additional hardware. The procedure simply consists in the optimization of the undulator gap configuration for each X-ray beamline. Here we provide a comprehensive description of the soft X-ray photon beam properties as a function of wavelength and bunch charge. Based on nominal parameters for the electron beam, we demonstrate that undulator tapering allows one to achieve up to a tenfold increase in peak power and photon spectral density in the conventional SASE regime. We illustrate this fact for the SASE3 beamline. The FEL code Genesis has been extensively used for these studies. Based on these findings we suggest that the requirements for the...

  3. Scheme for generation of highly monochromatic X-rays from a baseline XFEL undulator

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2010-01-01

    One goal of XFEL facilities is the production of narrow bandwidth X-ray radiation. The self-seeding scheme was proposed to obtain a bandwidth narrower than that achievable with conventional X-ray SASE FELs. A self-seeded FEL is composed of two undulators separated by a monochromator and an electron beam bypass that must compensate for the path delay of X-rays in the monochromator. This leads to a long bypass, with a length in the order of 40-60 m, which requires modifications of the baseline undulator configuration. As an attempt to get around this obstacle, together with a study of the self-seeding scheme for the European XFEL, here we propose a novel technique based on a pulse doubler concept. Using a crystal monochromator installed within a short magnetic chicane in the baseline undulator, it is possible to decrease the bandwidth of the radiation well beyond the XFEL design down to 10^(-5). The magnetic chicane can be installed without any perturbation of the XFEL focusing structure, and does not interfere...

  4. The full potential of the baseline SASE undulators of the European XFEL

    International Nuclear Information System (INIS)

    The output SASE characteristics of the baseline European XFEL, recently used in the TDRs of scientific instruments and X-ray optics, have been previously optimized assuming uniform undulators without considering the potential of undulator tapering in the SASE regime. Here we demonstrate that the performance of European XFEL sources can be significantly improved without additional hardware. The procedure simply consists in the optimization of the undulator gap configuration for each X-ray beamline. Here we provide a comprehensive description of the soft X-ray photon beam properties as a function of wavelength and bunch charge. Based on nominal parameters for the electron beam, we demonstrate that undulator tapering allows one to achieve up to a tenfold increase in peak power and photon spectral density in the conventional SASE regime. We illustrate this fact for the SASE3 beamline. The FEL code Genesis has been extensively used for these studies. Based on these findings we suggest that the requirements for the SASE3 instrument (SCS, SQS) and for the SASE3 beam transport system be updated.

  5. Nonlinear undulator tapering in conventional SASE regime at baseline electron beam parameters as a way to optimize the radiation characteristics of the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

    2013-09-15

    We demonstrate that the output radiation characteristics of the European XFEL sources at nominal operation point can be easily made significantly better than what is currently reported in the TDRs of scientific instruments and X-ray optics. In fact, the output SASE characteristics of the baseline European XFEL have been previously optimized assuming uniform undulators at a nominal operating point of 5 kA peak current, without considering the potential of undulator tapering in the SASE regime. In order to illustrate this point, we analyze the case of an electron bunch with nominal parameters. Based on start-to-end simulations, we demonstrate that nonlinear undulator tapering allows one to achieve up to a tenfold increase in peak power and photon spectral density in the conventional SASE regime, without modification to the baseline design. The FEL code Genesis has been extensively used for these studies. In order to increase our confidence in simulation results, we cross-checked outcomes by reproducing simulations in the deep nonlinear SASE regime with tapered undulator using the code ALICE.

  6. Nonlinear undulator tapering in conventional SASE regime at baseline electron beam parameters as a way to optimize the radiation characteristics of the European XFEL

    International Nuclear Information System (INIS)

    We demonstrate that the output radiation characteristics of the European XFEL sources at nominal operation point can be easily made significantly better than what is currently reported in the TDRs of scientific instruments and X-ray optics. In fact, the output SASE characteristics of the baseline European XFEL have been previously optimized assuming uniform undulators at a nominal operating point of 5 kA peak current, without considering the potential of undulator tapering in the SASE regime. In order to illustrate this point, we analyze the case of an electron bunch with nominal parameters. Based on start-to-end simulations, we demonstrate that nonlinear undulator tapering allows one to achieve up to a tenfold increase in peak power and photon spectral density in the conventional SASE regime, without modification to the baseline design. The FEL code Genesis has been extensively used for these studies. In order to increase our confidence in simulation results, we cross-checked outcomes by reproducing simulations in the deep nonlinear SASE regime with tapered undulator using the code ALICE.

  7. MaRIE Undulator & XFEL Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Laboratory; Marksteiner, Quinn R. [Los Alamos National Laboratory; Anisimov, Petr Mikhaylovich [Los Alamos National Laboratory; Buechler, Cynthia Eileen [Los Alamos National Laboratory

    2015-03-23

    The 22 slides in this presentation treat the subject under the following headings: MaRIE XFEL Performance Parameters, Input Electron Beam Parameters, Undulator Design, Genesis Simulations, Risks, and Summary It is concluded that time-dependent Genesis simulations show the MaRIE XFEL can deliver the number of photons within the required bandwidth, provided a number of assumptions are met; the highest risks are associated with the electron beam driving the XFEL undulator; and risks associated with the undulator and/or distributed seeding technique may be evaluated or retired by performing early validation experiments.

  8. Nonlinear undulator tapering in conventional SASE regime at baseline electron beam parameters as a way to optimize the radiation characteristics of the European XFEL

    CERN Document Server

    Serkez, Svitozar; Saldin, Evgeni; Zagorodnov, Igor; Geloni, Gianluca

    2013-01-01

    We demonstrate that the output radiation characteristics of the European XFEL sources at nominal operation point can be easily made significantly better than what is currently reported in the TDRs of scientific instruments and X-ray optics. In fact, the output SASE characteristics of the baseline European XFEL have been previously optimized assuming uniform undulators at a nominal operating point of 5 kA peak current, without considering the potential of udulator tapering in the SASE regime. In order to illustrate this point, we analyze the case of an electron bunch with nominal parameters. Based on start-to-end simulations, we demonstrate that nonlinear undulator tapering allows one to achieve up to a tenfold increase in peak power and photon spectral density in the conventional SASE regime, without modification to the baseline design. The FEL code Genesis has been extensively used for these studies. In order to increase our confidence in simulation results, we cross-checked outcomes by reproducing simulatio...

  9. Proposal to generate 10 TW level femtosecond X-ray pulses from a baseline undulator in conventional SASE regime at the European XFEL

    International Nuclear Information System (INIS)

    Output characteristics of the European XFEL have been previously studied assuming an operation point at 5 kA peak current. In this paper we explore the possibility to go well beyond such nominal peak current level. In order to illustrate the potential of the European XFEL accelerator complex we consider a bunch with 0.25 nC charge, compressed up to a peak current of 45 kA. An advantage of operating at such high peak current is the increase of the X-ray output peak power without any modification to the baseline design. Based on start-to-end simulations, we demonstrate that such high peak current, combined with undulator tapering, allows one to achieve up to a 100-fold increase in a peak power in the conventional SASE regime, compared to the nominal mode of operation. In particular, we find that 10 TW-power level, femtosecond x-ray pulses can be generated in the photon energy range between 3 keV and 5 keV, which is optimal for single biomolecule imaging. Our simulations are based on the exploitation of all the 21 cells foreseen for the SASE3 undulator beamline, and indicate that one can achieve diffraction to the desired resolution with 15 mJ (corresponding to about 3.1013 photons) in pulses of about 3 fs, in the case of a 100 nm focus at the photon energy of 3.5 keV.

  10. Proposal to generate 10 TW level femtosecond x-ray pulses from a baseline undulator in conventional SASE regime at the European XFEL

    CERN Document Server

    Serkez, Svitozar; Saldin, Evgeni; Zagorodnov, Igor; Geloni, Gianluca

    2013-01-01

    Output characteristics of the European XFEL have been previously studied assuming an operation point at 5 kA peak current. In this paper we explore the possibility to go well beyond such nominal peak current level. In order to illustrate the potential of the European XFEL accelerator complex we consider a bunch with 0.25 nC charge, compressed up to a peak current of 45 kA. An advantage of operating at such high peak current is the increase of the x-ray output peak power without any modification to the baseline design. Based on start-to-end simulations, we demonstrate that such high peak current, combined with undulator tapering, allows one to achieve up to a 100-fold increase in a peak power in the conventional SASE regime, compared to the nominal mode of operation. In particular, we find that 10 TW-power level, femtosecond x-ray pulses can be generated in the photon energy range between 3 keV and 5 keV, which is optimal for single biomolecule imaging. Our simulations are based on the exploitation of all the ...

  11. Undulator systems for the TESLA X-FEL

    International Nuclear Information System (INIS)

    A large X-ray FEL lab is under consideration within the TESLA project and is supposed to be operated in parallel with the TESLA linear collider. There will be five SASE FELs and five conventional spontaneous undulators. A conceptual design study has been made for the undulator systems for these X-FELs. It includes segmentation into 6.1 m long undulator 'cells'. Each consists of a 5 m long undulator 'segment', a separate quadrupole, one horizontal and one vertical corrector, and a phase shifter. These items are presented and discussed

  12. Purified SASE undulator configuration to enhance the performance of the soft x-ray beamline at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

    2013-08-15

    The purified SASE (pSASE) undulator configuration recently proposed at SLAC promises an increase in the output spectral density of XFELs. In this article we study a straightforward implementation of this configuration for the soft x-ray beamline at the European XFEL. A few undulator cells, resonant at a subharmonic of the FEL radiation, are used in the middle of the exponential regime to amplify the radiation, while simultaneously reducing the FEL bandwidth. Based on start-to-end simulations, we show that with the proposed configuration the spectral density in the photon energy range between 1.3 keV and 3 keV can be enhanced of an order of magnitude compared to the baseline mode of operation. This option can be implemented into the tunable-gap SASE3 baseline undulator without additional hardware, and it is complementary to the self-seeding option with grating monochromator proposed for the same undulator line, which can cover the photon energy range between about 0.26 keV and 1 keV.

  13. Circular polarization opportunities at the SASE3 undulator line of the European XFEL

    CERN Document Server

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni

    2016-01-01

    XFELs provide X-ray pulses with unprecedented peak brightness and ultrashort duration. They are usually driven by planar undulators, meaning that the output radiation is linearly polarized. For many experimental applications, however, polarization control is critical: besides the ability to produce linearly polarized radiation, one often needs the possibility of generating circularly polarized radiation with a high, stable degree of polarization. This may be achieved by using a first part of the XFEL undulator to produce bunching and then, by propagating the the bunched beam through an "afterburner" - a short undulator with tunable polarization, where only limited gain takes place. One of the issues that one needs to consider in this case is the separation of the circularly polarized radiation obtained in the radiator from the linearly polarized background produced in the first part of the FEL. In this article we review several methods to do so, including the inverse tapering technique. In particular, we use ...

  14. Automation of beam based alignment for the PAL-XFEL undulator line

    International Nuclear Information System (INIS)

    An automated method of quadrupole beam based alignment in an X-ray free electron laser (XFEL) undulator line is proposed. To realize the automatic beam based alignment (BBA) independently of operator's skill and efforts, the procedure is simplified. Simulation results on the BBA technique using two alignment stages for the Pohang Accelerator Laboratory XFEL's (PAL-XFEL) undulator line is carried out. After a standard mechanical alignment the quadrupoles are expected to be aligned to 100 μm rms from our previous experience. A rough alignment method in this study is able to align the quadrupoles to about 40 μm rms without any pre-handling of electron beam orbit or quadrupoles position. At the second stage, the singular value decomposition (SVD) method is applied to perform a fine alignment in which the trajectory of an electron beam is controlled within 5 μm rms to the ideal orbit. All procedures are programmable to perform the BBA automatically

  15. Longitudinal impedance and wake from XFEL undulators. Impact on current-enhanced SASE schemes

    International Nuclear Information System (INIS)

    In this article we derive longitudinal impedance and wake function for an undulator setup with arbitrary undulator parameter, taking into account a finite transverse size of the electron bunch. Earlier studies considered a line density-distribution of electrons instead. We focus our attention on the long-wavelength asymptote (compared with resonance wavelength), at large distance of the electron bunch from the undulator entrance compared to the overtaking length, and for large vacuumchamber size compared to the typical transverse size of the field. These restrictions define a parameter region of interest for practical applications. We calculate a closed expression for impedance and wake function that may be evaluated numerically in the most general case. Such expression allows us to derive an analytical solution for a Gaussian transverse and longitudinal bunch shape. Finally, we study the feasibility of current-enhanced SASE schemes (ESASE) recently proposed for LCLS, that fall well-within our approximations. Numerical estimations presented in this paper indicate that impedance-induced energy spread is sufficient to seriously degrade the FEL performance. Our conclusion is in contrast with results in literature, where wake calculations for the LCLS case are given in free-space, as if the presence of the undulator were negligible. (orig.)

  16. Longitudinal impedance and wake from XFEL undulators. Impact on current-enhanced SASE schemes

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, G.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

    2007-06-15

    In this article we derive longitudinal impedance and wake function for an undulator setup with arbitrary undulator parameter, taking into account a finite transverse size of the electron bunch. Earlier studies considered a line density-distribution of electrons instead. We focus our attention on the long-wavelength asymptote (compared with resonance wavelength), at large distance of the electron bunch from the undulator entrance compared to the overtaking length, and for large vacuumchamber size compared to the typical transverse size of the field. These restrictions define a parameter region of interest for practical applications. We calculate a closed expression for impedance and wake function that may be evaluated numerically in the most general case. Such expression allows us to derive an analytical solution for a Gaussian transverse and longitudinal bunch shape. Finally, we study the feasibility of current-enhanced SASE schemes (ESASE) recently proposed for LCLS, that fall well-within our approximations. Numerical estimations presented in this paper indicate that impedance-induced energy spread is sufficient to seriously degrade the FEL performance. Our conclusion is in contrast with results in literature, where wake calculations for the LCLS case are given in free-space, as if the presence of the undulator were negligible. (orig.)

  17. Photon beam properties at the European XFEL (December 2010 revision)

    Energy Technology Data Exchange (ETDEWEB)

    Schneidmiller, E.A.; Yurkov, M.V.

    2011-09-15

    A new set of baseline parameters of the electron beam and undulator for the European XFEL project has been defined recently. Changes refer to the electron beam emittance, charge, operation at different electron energies, and change of undulator period. According to the present concept, it is planned to vary charge from 20 pC to 1 nC allowing control of the FWHM radiation pulse duration. Operation at different electron energies of 17.5 GeV, 14 GeV, and 10.5 GeV will allow extension of the wavelength range to longer wavelengths. Electron bunches with different charges possess different properties. These features have an impact on photon beam properties which should be taken into account at the design stage optical beamlines and instruments and planning user experiments. In this note we present an overview of the radiation properties generated by SASE FEL radiators driven by electron beam with revised baseline parameters. (orig.)

  18. Circular polarization control for the European XFEL in the soft X-ray regime

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2011-01-01

    The possibility of producing highly circularly polarized X-ray radiation, especially in the soft X-ray region, is an important asset at XFELs. However, the baseline of the European XFEL, including the soft X-ray SASE3 line, foresees planar undulators only. The lowest-risk strategy for implementing polarization control at SASE3 involves adding an APPLE II-type undulator at the end of the planar undulator, to exploit the microbunching from the baseline FEL. 5m-long APPLE II undulators are standard devices at synchrotrons. However, the choice of a short helical radiator leads to the problem of background suppression. The driving idea of our proposal is that the background radiation can be suppressed by spatial filtering. Slits can be inserted behind the APPLE II radiator, where the linearly-polarized radiation spot size is about 30 times larger than the radiation spot size from the helical radiator. The last 7 cells of the SASE3 undulator are left with an open gap in order to provide a total 42 m drift section f...

  19. Prospects for CW and LP operation of the European XFEL in hard X-ray regime

    CERN Document Server

    Brinkmann, R; Sekutowicz, J; Yurkov, M V

    2014-01-01

    The European XFEL will operate nominally at 17.5 GeV in SP (short pulse) mode with 0.65 ms long bunch train and 10 Hz repetition rate. A possible upgrade of the linac to CW (continuous wave) or LP (long pulse) modes with a corresponding reduction of electron beam energy is under discussion since many years. Recent successes in the dedicated R&D program allow to forecast a technical feasibility of such an upgrade in the foreseeable future. One of the challenges is to provide sub-Angstrom FEL operation in CW and LP modes. In this paper we perform a preliminary analysis of a possible operation of the European XFEL in the hard X-ray regime in CW and LP modes with the energies of 7 GeV and 10 GeV, respectively. We consider lasing in the baseline XFEL undulator as well as in a new undulator with a reduced period. We show that, with reasonable requirements on electron beam quality, lasing on the fundamental will be possible in sub-Angstrom regime. As an option for generation of brilliant photon beams at short wa...

  20. Prospects for CW and LP operation of the European XFEL in hard X-ray regime

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, R.; Schneidmiller, E.A.; Sekutowicz, J.; Yurkov, M.V.

    2014-03-15

    The European XFEL will operate nominally at 17.5 GeV in SP (short pulse) mode with 0.65 ms long bunch train and 10 Hz repetition rate. A possible upgrade of the linac to CW (continuous wave) or LP (long pulse) modes with a corresponding reduction of electron beam energy is under discussion since many years. Recent successes in the dedicated R and D program allow to forecast a technical feasibility of such an upgrade in the foreseeable future. One of the challenges is to provide sub-Aangstrom FEL operation in CW and LP modes. In this paper we perform a preliminary analysis of a possible operation of the European XFEL in the hard X-ray regime in CW and LP modes with the energies of 7 GeV and 10 GeV, respectively. We consider lasing in the baseline XFEL undulator as well as in a new undulator with a reduced period. We show that, with reasonable requirements on electron beam quality, lasing on the fundamental will be possible in sub-Aangstrom regime. As an option for generation of brilliant photon beams at short wavelengths we also consider harmonic lasing that has recently attracted a significant attention.

  1. Perspectives for imaging single protein molecules with the present design of the European XFEL

    Directory of Open Access Journals (Sweden)

    Kartik Ayyer

    2015-07-01

    Full Text Available The Single Particles, Clusters and Biomolecules & Serial Femtosecond Crystallography (SPB/SFX instrument at the European XFEL is located behind the SASE1 undulator and aims to support imaging and structure determination of biological specimen between about 0.1 μm and 1 μm size. The instrument is designed to work at photon energies from 3 keV up to 16 keV. Here, we propose a cost-effective proof-of-principle experiment, aiming to demonstrate the actual feasibility of a single molecule diffraction experiment at the European XFEL. To this end, we assume self-seeding capabilities at SASE1 and we suggest to make use of the baseline European XFEL accelerator complex—with the addition of a slotted-foil setup—and of the SPB/SFX instrument. As a first step towards the realization of an actual experiment, we developed a complete package of computational tools for start-to-end simulations predicting its performance. Single biomolecule imaging capabilities at the European XFEL can be reached by exploiting special modes of operation of the accelerator complex and of the SASE1 undulator. The output peak power can be increased up to more than 1.5 TW, which allows to relax the requirements on the focusing efficiency of the optics and to reach the required fluence without changing the present design of the SPB/SFX instrument. Explicit simulations are presented using the 15-nm size RNA Polymerase II molecule as a case study. Noisy diffraction patterns were generated and they were processed to generate the 3D intensity distribution. We discuss requirements to the signal-to-background ratio needed to obtain a correct pattern orientation. When these are fulfilled, our results indicate that one can achieve diffraction without destruction with about 0.1 photons per Shannon pixel per shot at 4 Å resolution with 1013 photons in a 4 fs pulse at 4 keV photon energy and in a 0.3 μm focus, corresponding to a fluence of 1014 photons/μm2. We assume

  2. The European XFEL project

    International Nuclear Information System (INIS)

    The European XFEL project is a 4th generation synchrotron radiation facility based on the SASE FEL concept and the superconducting TESLA technology for a linear accelerator. In February 2003 the German government decided that the XFEL should be realized as a European project and be located at DESY in Hamburg. The paper will give an overview of the overall layout and parameters of the facility, with emphasis on the accelerator design, technology and physics. (author)

  3. Plasma undulator

    International Nuclear Information System (INIS)

    Two types of the undulator which is developed as a generator of the highly brilliant light for the synchrotron radiation sources and the free electron lasers, are newly proposed using the array of slender plasmas columns. One is the magnetic field type, in which the undulator force on the relativistic electron beam is generated with the electric current flowing through the plasma columns. The other is the electric field type, in which the undulator force is generated with the periodic variation of the density between the slender plasma columns. The production methods and stabilization ones of plasma columns are discussed. (author)

  4. Scheme for generating and transporting THz radiation to the X-ray experimental hall at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Decking, Winfried; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

    2011-12-15

    The design of a THz edge radiation source for the European XFEL is presented.We consider generation of THz radiation from the spent electron beam downstream of the SASE2 undulator in the electron beam dump area. In this way, the THz output must propagate at least for 250 meters through the photon beam tunnel to the experimental hall to reach the SASE2 X-ray hutches. We propose to use an open beam waveguide such as an iris guide as transmission line. In order to efficiently couple radiation into the iris transmission line, generation of the THz radiation pulse can be performed directly within the iris guide. The line transporting the THz radiation to the SASE2 X-ray hutches introduces a path delay of about 20 m. Since THz pump/X-ray probe experiments should be enabled, we propose to exploit the European XFEL baseline multi-bunch mode of operation, with 222 ns electron bunch separation, in order to cope with the delay between THz and X-ray pulses. We present start-to-end simulations for 1 nC bunch operation-parameters, optimized for THz pump/X-ray probe experiments.Detailed characterization of the THz and SASE X-ray radiation pulses is performed. Highly focused THz beams will approach the high field limit of 1 V/atomic size. (orig.)

  5. PAL-XFEL cavity beam position monitor pick-up design and beam test

    Science.gov (United States)

    Lee, Sojeong; Park, Young Jung; Kim, Changbum; Kim, Seung Hwan; Shin, Dong Cheol; Han, Jang-Hui; Ko, In Soo

    2016-08-01

    As an X-ray Free Electron Laser, PAL-XFEL is about to start beam commissioning. X-band cavity beam position monitor (BPM) is used in the PAL-XFEL undulator beam line. Prototypes of cavity BPM pick-up were designed and fabricated to test the RF characteristics. Also, the beam test of a cavity BPM pick-up was done in the Injector Test Facility (ITF). In the beam test, the raw signal properties of the cavity BPM pick-up were measured at a 200 pC bunch charge. According to the RF test and beam test results, the prototype cavity BPM pick-up design was confirmed to meet the requirements of the PAL-XFEL cavity BPM system.

  6. Hybrid undulator numerical optimization

    Energy Technology Data Exchange (ETDEWEB)

    Hairetdinov, A.H. [Kurchatov Institute, Moscow (Russian Federation); Zukov, A.A. [Solid State Physics Institute, Chernogolovka (Russian Federation)

    1995-12-31

    3D properties of the hybrid undulator scheme arc studied numerically using PANDIRA code. It is shown that there exist two well defined sets of undulator parameters which provide either maximum on-axis field amplitude or minimal higher harmonics amplitude of the basic undulator field. Thus the alternative between higher field amplitude or pure sinusoidal field exists. The behavior of the undulator field amplitude and harmonics structure for a large set of (undulator gap)/(undulator wavelength) values is demonstrated.

  7. The BINP HLS to measurement vertical changes on PAL-XFEL building and ground

    CERN Document Server

    Choi, Hyo-Jin; Gil, Kye-Hwan; Kim, Seung-Hwan; Kang, Heung-Sik

    2016-01-01

    PAL-XFEL, a 4th generation light source, is currently being installed and will be completed by December of 2015 so that users can be supported beginning in 2016. PAL-XFEL equipment should continuously maintain the bunch-to-bunch beam parameter (60Hz, Energy 10GeV, Charge 200pC, Bunch Length 60fs, Emittance X/Y 0.481mm/0.256mm rad) in order to supply the energy, flux and timing of stable photons in tests by beam line users. To this end, PAL-XFEL equipment has to be kept precisely aligned (Linear Accelerator +/- 100um, Undulator +/- 50um). As a part of the process for installing PAL-XFEL, a GPS-used surface geodetic network is being constructed for precise equipment measurement and alignment, and the installation of a tunnel measurement network inside buildings is in preparation; additionally, the fiducialization of major equipment is underway. After PAL-XFEL equipment is optimized and aligned, if the ground and buildings go through vertical changes during operation, misalignment (and tilt) of equipment includi...

  8. Circular polarization control for the LCLS baseline in the soft X-ray regime

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-12-15

    restricted to the LCLS baseline setup. Other facilities e. g. LCLS II or the European XFEL may benefit from this work as well, due to availability of sufficiently long free space at the end of undulator tunnel. (orig.)

  9. Statistical properties of the radiation from SASE FEL operating in a post-saturation regime with and without undulator tapering

    CERN Document Server

    Schneidmiller, E A

    2015-01-01

    We describe statistical and coherence properties of the radiation from x-ray free electron lasers (XFEL) operating in the post-saturation regime. We consider practical case of the SASE3 FEL at the European XFEL. We perform comparison of the main characteristics of the X-ray FEL operating in the post-saturation regime with and without undulator tapering: efficiency, coherence time and degree of transverse coherence.

  10. XFEL OSCILLATOR SIMULATION INCLUDING ANGLE-DEPENDENT CRYSTAL REFLECTIVITY

    International Nuclear Information System (INIS)

    The oscillator package within the GINGER FEL simulation code has now been extended to include angle-dependent reflectivity properties of Bragg crystals. Previously, the package was modified to include frequencydependent reflectivity in order to model x-ray FEL oscillators from start-up from shot noise through to saturation. We present a summary of the algorithms used for modeling the crystal reflectivity and radiation propagation outside the undulator, discussing various numerical issues relevant to the domain of high Fresnel number and efficient Hankel transforms. We give some sample XFEL-O simulation results obtained with the angle-dependent reflectivity model, with particular attention directed to the longitudinal and transverse coherence of the radiation output.

  11. Prototype screen monitor for XFEL/SPring-8

    International Nuclear Information System (INIS)

    A prototype screen monitor for XFEL/SPring-8 is developed and verified at the SCSS test accelerator. The imaging apparatus has a high-resolution (<10um) optical system with variable magnification of 1.2x-4x. In order to change the magnification ratio by remote control, a lens and an imaging device are mounted on motorized stages. The screen actuator can hold two screen targets, an OTR target and a fluorescent plate target, and can switch them by an air cylinder. We developed a thin OTR target made of 100um-thick stainless-steel foil in order to reduce demagnetization of undulator magnets due to scattered particles at the target. We performed a beam experiment of the prototype screen monitor with the thin OTR target at the SCSS test accelerator and we appropriately obtained an electron beam profile. (author)

  12. High harmonics focusing undulator

    Energy Technology Data Exchange (ETDEWEB)

    Varfolomeev, A.A.; Hairetdinov, A.H.; Smirnov, A.V.; Khlebnikov, A.S. [Kurchatov Institute, Moscow (Russian Federation)

    1995-12-31

    It was shown in our previous work that there exist a possibility to enhance significantly the {open_quote}natural{close_quote} focusing properties of the hybrid undulator. Here we analyze the actual undulator configurations which could provide such field structure. Numerical simulations using 2D code PANDIRA were carried out and the enhanced focusing properties of the undulator were demonstrated. The obtained results provide the solution for the beam transport in a very long (short wavelength) undulator schemes.

  13. XFEL/Short Pulse Science

    CERN Document Server

    Schneider, Jochen

    2005-01-01

    X-rays are a most powerful tool for 3 dimensional imaging of matter on length scales from mm to nanometer. They allow for highly accurate determination of the position of atoms and their correlated motion in samples with complex structure under extreme temperature or pressure condi-tions, they probe either bulk or surface properties including order-disorder phenomena. With high resolution spectro-microscopy electronic properties of inhomogeneous novel materials are studied in great detail. So far equilibrium states are investigated. The logical next step is to extend our methodology to include the investigation of non-equilibrium, of new states of matter with atomic resolution in space and time. The XFELs provide the necessary very intense flashes of X-rays with wave-lengths down to 0.1 nm with pulse durations of 10 or 100 femtoseconds. Examples of the sug-gested applications of XFELs will be presented. Strategies for performing experiments at LINAC driven light sources will be discussed with emphasis on the ...

  14. Tuning The Laser Heater Undulator

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Zackary

    2010-12-03

    The laser heater undulator for the LCLS requires different tuning techniques than the main undulators. It is a pure permanent magnet (PPM) undulator, rather than the hybrid design of the main undulators. The PPM design allows analytic calculation of the undulator fields. The calculations let errors be introduced and correction techniques be derived. This note describes how the undulator was modelled, and the methods which were found to correct potential errors in the undulator. The laser heater undulator for the LCLS is a pure permanent magnet device requiring different tuning techniques than the main undulators. In this note, the laser heater undulator is modelled and tuning techniques to compensate various errors are derived.

  15. Modulated electron bunch with amplitude front tilt in an undulator

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-12-15

    In a previous paper we discussed the physics of a microbunched electron beam kicked by the dipole field of a corrector magnet by describing the kinematics of coherent undulator radiation after the kick. We demonstrated that the effect of aberration of light supplies the basis for understanding phenomena like the deflection of coherent undulator radiation by a dipole magnet. We illustrated this fact by examining the operation of an XFEL under the steady state assumption, that is a harmonic time dependence. We argued that in this particular case the microbunch front tilt has no objective meaning; in other words, there is no experiment that can discriminate whether an electron beam is endowed with a microbunch front tilt of not. In this paper we extend our considerations to time-dependent phenomena related with a finite electron bunch duration, or SASE mode of operation. We focus our attention on the spatiotemporal distortions of an X-ray pulse. Spatiotemporal coupling arises naturally in coherent undulator radiation behind the kick, because the deflection process involves the introduction of a tilt of the bunch profile. This tilt of the bunch profile leads to radiation pulse front tilt, which is equivalent to angular dispersion of the output radiation. We remark that our exact results can potentially be useful to developers of new generation XFEL codes for cross-checking their results.

  16. Extension of self-seeding to hard X-rays >10 keV as a way to increase user access at the European XFEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2011-01-01

    We propose to use the self-seeding scheme with single crystal monochromator at the European X-ray FEL to produce monochromatic, high-power radiation at 16 keV. Based on start to end simulations we show that the FEL power of the transform-limited pulses can reach about 100 GW by exploiting tapering in the tunable-gap baseline undulator. The combination of high photon energy, high peak power, and very narrow bandwidth opens a vast new range of applications, and includes the possibility to considerably increase the user capacity and fully exploit the high repetition rate of the European XFEL. In fact, dealing with monochromatic hard X-ray radiation one may use crystals as deflectors with minimum beam loss. To this end, a photon beam distribution system based on the use of crystals in the Bragg reflection geometry is proposed for future study and possible extension of the baseline facility. They can be repeated a number of times to form an almost complete (one meter scale) ring with an angle of 20 degrees between...

  17. Machine protection for FLASH and the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Lars

    2009-05-15

    The Free-Electron Laser in Hamburg (FLASH) and the future European X-Ray Free-Electron Laser (XFEL) are sources of brilliant extremeultraviolet and X-ray radiation pulses. Both facilities are based on superconducting linear accelerators (linacs) that can produce and transport electron beams of high average power. With up to 90 kW or up to 600 kW of power, respectively, these beams hold a serious potential to damage accelerator components. This thesis discusses several passive and active machine protection measures needed to ensure safe operation. At FLASH, dark current from the rf gun electron source has activated several accelerator components to unacceptable radiation levels. Its transport through the linac is investigated with detailed tracking simulations using a parallelized and enhanced version of the tracking code Astra; possible remedies are evaluated. Beam losses can lead to the demagnetization of permanent magnet insertion devices. A number of beam loss scenarios typical for FLASH are investigated with shower simulations. A shielding setup is designed and its efficiency is evaluated. For the design parameters of FLASH, it is concluded that the average relative beam loss in the undulators must be controlled to a level of about 10{sup -8}. FLASH is equipped with an active machine protection system (MPS) comprising more than 80 photomultiplier-based beam loss monitors and several subsystems. The maximum response time to beam losses is less than 4 {mu}s. Setup procedures and calibration algorithms for MPS subsystems and components are introduced and operational problems are addressed. Finally, an architecture for a fully programmable machine protection system for the XFEL is presented. Several options for the topology of this system are reviewed, with the result that an availability goal of at least 0.999 for the MPS is achievable with moderate hardware requirements. (orig.)

  18. Machine protection for FLASH and the European XFEL

    International Nuclear Information System (INIS)

    The Free-Electron Laser in Hamburg (FLASH) and the future European X-Ray Free-Electron Laser (XFEL) are sources of brilliant extremeultraviolet and X-ray radiation pulses. Both facilities are based on superconducting linear accelerators (linacs) that can produce and transport electron beams of high average power. With up to 90 kW or up to 600 kW of power, respectively, these beams hold a serious potential to damage accelerator components. This thesis discusses several passive and active machine protection measures needed to ensure safe operation. At FLASH, dark current from the rf gun electron source has activated several accelerator components to unacceptable radiation levels. Its transport through the linac is investigated with detailed tracking simulations using a parallelized and enhanced version of the tracking code Astra; possible remedies are evaluated. Beam losses can lead to the demagnetization of permanent magnet insertion devices. A number of beam loss scenarios typical for FLASH are investigated with shower simulations. A shielding setup is designed and its efficiency is evaluated. For the design parameters of FLASH, it is concluded that the average relative beam loss in the undulators must be controlled to a level of about 10-8. FLASH is equipped with an active machine protection system (MPS) comprising more than 80 photomultiplier-based beam loss monitors and several subsystems. The maximum response time to beam losses is less than 4 μs. Setup procedures and calibration algorithms for MPS subsystems and components are introduced and operational problems are addressed. Finally, an architecture for a fully programmable machine protection system for the XFEL is presented. Several options for the topology of this system are reviewed, with the result that an availability goal of at least 0.999 for the MPS is achievable with moderate hardware requirements. (orig.)

  19. Undulators for SASE FELs

    CERN Document Server

    Pflüger, J

    2000-01-01

    In this contribution, the requirements on undulators for linac driven SASE FELs will be discussed. Differences between long and short wavelength SASE FELs will be worked out. The problematic influencing the choice of minimum gap and undulator peak field which are special for SASE FELs driven by multi GeV electron beams with sub picosecond pulses, peak currents of several kiloamperes will be pointed out. Special attention is given to the magnetic design of combined strong focusing undulators as are needed for VUV FELs. As an example results will be presented of the undulator for the VUV-FEL at the TESLA Test Facility which has just been completed.

  20. Development status of the X-ray beam diagnostics devices for the commissioning and user operation of the European XFEL

    International Nuclear Information System (INIS)

    X-ray Free-Electron-Lasers (XFEL) as the Linac Coherent Light Source (LCLS) in the USA, SACLA in Japan, and the European XFEL under construction in Germany are 4th generation light sources which allow research of at the same time extremely small structures (Ångström resolution) and extremely fast phenomena (femtosecond resolution). Unlike the pulses from a conventional optical laser, the radiation in these sources is created by the Self-Amplified Spontaneous Emission (SASE) process when electron bunches pass through very long segmented undulators. The shot noise at the origin of this process leads to significant pulse-to-pulse variations of pulse intensity, spectrum, wavefront, temporal properties etc. so that for user experiments an online monitoring of these properties is mandatory. Also, the adjustment of the long segmented undulators requires dedicated diagnostics such as an undulator commissioning spectrometer and spontaneous radiation analysis. The extremely high brilliance and resulting single-shot damage issue are difficult to handle for any XFEL diagnostics. Apart from the large energy range of operation of the facility from 280 eV to 25 keV in FEL fundamental, the particular challenge for the European XFEL diagnostics is the high intra bunch train photon pulse repetition rate of 4.5 MHz, potentially causing additional damage by high heat loads and making shot-to-shot diagnostics very demanding. This contribution reports on the facility concepts, recent progress in instrumentation development, and the optimization of diagnostics performance with respect to resolution/accuracy, shot-to-shot capabilities and energy range.

  1. JSR undulator experiment

    International Nuclear Information System (INIS)

    JSR has an 1.5m long straight section for a insertion device. An undulator was installed in this straight section in July, 1991. The first observation of spontaneous radiation from this undulator was performed in August. The wavelength change due to K-parameter change was measured at the beam energy of 138.9MeV and 174.6MeV, and also measured was the tune shift due to the undulator insertion. These experimental results are in good agreements with calculations. (author)

  2. Large-bandwidth data acquisition network for XFEL facility, SACLA

    International Nuclear Information System (INIS)

    The SACLA (SPring-8 Angstrom Compact Free Electron Laser) facility consists of an accelerator building, an undulator building and an experimental facility. SACLA is designed to produce X-ray with a wavelength as short as 0.06 nm and with a repetition rate of 60 Hz. X-ray Free-Electron Laser (XFEL) experiments demands large bandwidth network for data acquisition (DAQ). At SACLA the experimental data rate is to be up to 5.8 Giga bit per second (Gbps). Some of the experiments demands preprocessing and on-line analysis by high-performance computers. In order to fulfill these requirements, a dedicated network system for DAQ and data analysis has been developed. A DAQ network consists of a dedicated 10 Gbps Ethernet (10 GbE) physical layer to secure the data bandwidth and a 1 GbE layer for instrument controls. The DAQ network is connected to a primary storage and indirectly to a PC cluster for data preprocessing. A fire-wall system with virtual private network (VPN) features is also implemented in order to secure remote access from off-site institutes. The use of a large-bandwidth data transfer technique allows the efficient transfer of pre-processed data from SACLA to an off-site supercomputer

  3. Investigation of a free electron laser oscillator in the X-ray wavelength regime for the European XFEL; Untersuchungen zu einem Freie-Elektronen-Laser-Oszillator im Roentgen-Wellenlaengenbereich fuer den European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Zemella, Johann Christian Uwe

    2013-09-15

    In this thesis an X-ray free electron laser oscillator for the European XFEL is described. Such an oscillator consists of at least two Bragg deflecting crystals, in this content two or four Diamond crystals, focussing mirrors and an undulator. The advantage of Diamond is caused by the high reflectivity and the high thermal conductivity, which is necessary for dissipate the absorbed energy out of the center of the crystal. In context of this thesis the principle layout of an XFELO for the European XFEL and the FEL process is presented. Effects on the FEL process due to the disturbances of the electron beam or the XFELO cavity are discussed. As second aspect the thermal evolution in the crystal under absorbed XFELO-pulses is investigated. An experiment for the investigation of the thermal evolution of crystals under simulated XFELO conditions is presented.

  4. Possible operation of the European XFEL with ultra-low emittance beams

    International Nuclear Information System (INIS)

    Recent successful lasing of the Linac Coherent Light Source (LCLS) in the hard x-ray regime and the experimental demonstration of a possibility to produce low-charge bunches with ultra-small normalized emittance have lead to the discussions on optimistic scenarios of operation of the European XFEL. In this paper we consider new options that make use of low-emittance beams, a relatively high beam energy, tunable-gap undulators, and a multibunch capability of this facility. We study the possibility of operation of a spontaneous radiator (combining two of them, U1 and U2, in one beamline) in the SASE mode in the designed photon energy range 20-90 keV and show that it becomes possible with ultra-low emittance electron beams similar to those generated in LCLS. As an additional attractive option we consider the generation of powerful soft X-ray and VUV radiation by the same electron bunch for pump-probe experiments, making use of recently invented compact afterburner scheme. We also propose a betatron switcher as a simple, cheap, and robust solution for multi-color operation of SASE1 and SASE2 undulators, allowing to generate 2 to 5 X-ray beams of different independent colors from each of these undulators for simultaneous multi-user operation. We describe a scheme for pump-probe experiments, based on a production of two different colors by two closely spaced electron bunches (produced in photoinjector) with the help of a very fast betatron switcher. Finally, we discuss how without significant modifications of the layout the European XFEL can become a unique facility that continuously covers with powerful, coherent radiation a part of the electromagnetic spectrum from far infrared to gamma-rays. (orig.)

  5. Design Study of Beijing XFEL Test Facility

    CERN Document Server

    Dai, J P

    2005-01-01

    As R&D of X-ray Free Electron Laser facility in China, the construction of Beijing XFEL Test Facility (BTF) has been proposed. And the start to end simulation of BTF was made with codes PARMELA, ELEGANT and TDA. This paper presents the motivation, the scheme and the simulation results of BTF.

  6. The JLAB UV Undulator

    Energy Technology Data Exchange (ETDEWEB)

    Gottschalk, Steven C. [STI, Washington, USA; Benson, Steven V. [JLAB; Moore, Steven Wesley [JLAB

    2013-05-01

    Recently the JLAB FEL has demonstrated 150 W at 400 nm and 200 W at 700 nm using a 33mm period undulator designed and built by STI Optronics. This paper describes the undulator design and performance. Two key requirements were low phase error, zero steering and offset end fields and small rms trajectory errors. We will describe a new genetic algorithm that allowed phase error minimization to 1.8 degrees while exceeding specifications. The mechanical design, control system and EPICS interface will also be summarized.

  7. Self-Stimulated Undulator Klystron

    OpenAIRE

    Bessonov, E. G.; Osipov, A. L.; Mikhailichenko, A. A.

    2011-01-01

    The Self Stimulated Undulator Klystron (SSUK) and its possible applications in the Particle Accelerator Physics, incoherent Self-Stimulated Undulator Radiation Sources (SSUR) and Free-Electron Lasers (FEL) are discussed.

  8. A Novel Diagnostics of Ultrashort Electron Bunches Based on Detection of Coherent Radiation from Bunched Electron Beam in an Undulator

    CERN Document Server

    Saldin, Evgeny L; Yurkov, Mikhail V

    2004-01-01

    We propose a new method for measurements of the longitudinal profile of 100 femtosecond electron bunches for X-ray Free Electron Lasers (XFELs). The method is based on detection of coherent undulator radiation produced by modulated electron beam. Seed optical quantum laser is used to produce exact optical replica of ultrashort electron bunches. The replica is generated in apparatus which consists of an input undulator (energy modulator), and output undulator (radiator) separated by a dispersion section. The radiation in the output undulator is excited by the electron bunch modulated at the optical wavelength and rapidly reaches a hundred-MW-level power. We then use the now-standard method of ultrashort laser pulse-shape measurement, a tandem combination of autocorrelator and spectrum (FROG -- frequency resolved optical gating) providing real-time single-shot measurements of the electron bunch structure. The big advantage of proposed technique is that it can be used to determine the slice energy spread and emi...

  9. High frequency impedances in European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Dohlus, Martin; Zagorodnov, Igor; Zagorodnova, Olga

    2010-06-15

    The method of the optical approximation is used to estimate the high frequency impedances of different vacuum chamber transitions of the European XFEL beam line. The approximations of the longitudinal impedances are obtained in terms of simple one-dimensional integrals. The transverse impedances are written in analytical closed form. The analytical results are compared with the results obtained by numerical solution of Maxwell's equations. (orig.)

  10. CW Energy Recovery Operation of XFELs

    Energy Technology Data Exchange (ETDEWEB)

    Jacek Sekutowicz; S. Bogacz; Dave Douglas; Peter Kneisel; Gwyn P. Wiliams; Massimo Ferrario; Luca Serafini; Ilan Ben-Zvi; James Rose; Triveni Srinivasan-Rao; Patrick Colestock; Wolf-Dietrich Moeller; Bernd Petersen; Dieter Proch; S. Simrock; James B. Rosenzweig

    2003-09-01

    Commissioning of two large coherent light facilities at SLAC and DESY should begin in 2008 and in 2011 respectively. In this paper we look further into the future, hoping to answer, in a very preliminary way, two questions. First: What will the next generation of the XFEL facilities look like ? Believing that super-conducting technology offers several advantages over room-temperature technology, such as high quality beams with highly populated bunches and the possibility of energy recovery or higher overall efficiency, we focus this preliminary study on the superconducting option. From this belief the second question arises: ''What modifications in superconducting technology and in machine design are needed, as compared to the present DESY XFEL, and what kind of R&D program is required over the next few years to arrive at a technically feasible solution with even higher brilliance and increased overall conversion of AC power to photon beam power. In this paper we will very often refer to and profit from the DESY XFEL design, acknowledging its many technically innovative solutions.

  11. Modelling of undulator sources

    International Nuclear Information System (INIS)

    We present a new code capable of realistically modelling the radiation from ideal undulator sources, including explicit electron emittance effects. The code has been developed as part of the SHADOW X-ray optics ray tracing program, in order to predict the performances of undulator-based optical systems. The approach is based on a simplified field distribution that allows an efficient calculation of the trajectory and of the radiation field. We show explicitly that the undulator radiation pattern is shift-invariant with respect to the electron trajectory angles, so that the emittance effects can be included without recomputing the radiation distribution. Furthermore, the time consuming computation of the undulator emission patterns is decoupled from the Monte Carlo sampling of the wavefront, leading to a very fast code. This is achieved by computing the three-dimensional source probability distribution function and by using an inversion algorithm to generate a random variate with the same distribution as the source. The physical basis of the code and the algorithm used are discussed in detail and some results presented

  12. Modulated Electron Bunch with Amplitude Front Tilt in an Undulator

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2015-01-01

    In a previous paper we discussed the physics of a microbunched electron beam kicked by the dipole field of a corrector magnet by describing the kinematics of coherent undulator radiation after the kick. We demonstrated that the effect of aberration of light supplies the basis for understanding phenomena like the deflection of coherent undulator radiation by a dipole magnet. We illustrated this fact by examining the operation of an XFEL under the steady state assumption, that is a harmonic time dependence. We argued that in this particular case the microbunch front tilt has no objective meaning; in other words, there is no experiment that can discriminate whether an electron beam is endowed with a microbunch front tilt of not. In this paper we extend our considerations to time-dependent phenomena related with a finite electron bunch duration, or SASE mode of operation. We focus our attention on the spatiotemporal distortions of an X-ray pulse. Spatiotemporal coupling arises naturally in coherent undulator radi...

  13. Corrugated structure insertion for extending the SASE bandwidth up to 3% at the European XFEL

    CERN Document Server

    Zagorodnov, I; Limberg, T

    2016-01-01

    The usage of x-ray free electron laser (XFEL) in femtosecond nanocrystallography involves sequential illumination of many small crystals of arbitrary orientation. Hence a wide radiation bandwidth will be useful in order to obtain and to index a larger number of Bragg peaks used for determination of the crystal orientation. Considering the baseline configuration of the European XFEL in Hamburg, and based on beam dynamics simulations, we demonstrate here that the usage of corrugated structures allows for a considerable increase in radiation bandwidth. Data collection with a 3% bandwidth, a few microjoule radiation pulse energy, a few femtosecond pulse duration, and a photon energy of 5.4 keV is possible. For this study we have developed an analytical modal representation of the short-range wake function of the flat corrugated structures for arbitrary offsets of the source and the witness particles.

  14. Electronics for the European XFEL: AGIPD a high frame rate camera

    International Nuclear Information System (INIS)

    The European free electron laser (EuXFEL) facility will generate coherent and intense X-ray flashes at rates up to 27 000 per second. X-rays flashes are generated by passing bunches of electrons, accelerated to 17.5GeV by a superconducting linear accelerator, through magnetic undulators in which electrons emit X-ray flashes by a SASE lasing process. Each flash is intense enough to produce a full diffractive picture of scattering targets, such as biological molecules, which, when reconstructed, will allow new insights into material structure and dynamics. Dedicated two dimensional area camera systems, e.g. AGIPD, are being developed to record up to 5000 images/second with a resolution of 1Mega-Pixel and a dynamic range of 0-104 photons/pixel. This talk will present the accelerator and detector techniques used and will emphasis the electronics developments being made.

  15. Numerical Modeling of Shoreline Undulations

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg

    length of the shoreline undulations is determined in the linear regime using a shoreline stability analysis based on the numerical model. The analysis shows that the length of the undulations in the linear regime depends on the incoming wave conditions and on the coastal profile. For larger waves and...... relationship between the shoreline undulations and longshore bars and the relationship between the morphology and the hydrodynamics. In one of the data sets the shoreline undulations are well correlated with undulations on the depth contours between -5 m and +2 m relative to mean sea level. An analysis of the...

  16. The task of beam abort module optical link network for XFEL safety interlock system

    International Nuclear Information System (INIS)

    X-ray Free Electron Laser (XFEL) facility will provide an environment to experiment using high coherent X-ray laser beam, which is generated by electron beam accelerated by a linear accelerator, passing the undulator. The XFEL facility (SACLA) which is constructed at SPring-8 site, is necessary to build the two interlock systems for human radiation protection. One is accelerator safety interlock system to ensure the safety of the accelerator housing portion. Another is the beamline interlock system to ensure the safety of beamlines and experimental hutch. Two interlock systems, alone or together, stop the accelerator, to ensure the safety of facility. This system can stop the accelerator at high speed, using high-speed stop signal optical transmission equipments connected in series, without PLC. The high-speed stop signal optical transmission equipment was designed and has achieved, to be within 5 ms delay time, when connected in series 70 equipments. This paper reports about the role and characteristics of the high-speed stop signal optical transmission equipment. (author)

  17. Scheme to increase the output average spectral flux of the European XFEL at $14.4$ keV

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2015-01-01

    Techniques like inelastic X-ray scattering (IXS) and nuclear resonance scattering (NRS) are currently limited by the photon flux available at X-ray sources. At $14.4$ keV, third generation synchrotron radiation sources produce a maximum of $10^{10}$ photons per second in a meV bandwidth. In this work we discuss about the possibility of increasing this flux a thousand-fold by exploiting high repetition rate self-seeded pulses at the European XFEL. Here we report on a feasibility study for an optimized configuration of the SASE2 beamline at the European XFEL which combines self-seeding and undulator tapering techniques in order to increase the average spectral flux at $14.4$ keV. In particular, we propose to perform monochromatization at $7.2$ keV with the help of self-seeding, and amplify the seed in the first part of output undulator. The amplification process can be stopped at a position well before saturation, where the electron beam gets considerable bunching at the 2nd harmonic of the coherent radiation. ...

  18. Undulators at the ALS

    International Nuclear Information System (INIS)

    At Lawrence Berkeley Laboratory's (LBL) Advanced Light Source (ALS), three 4.6 m long undulators have been completed, tested and installed. A fourth is under construction. The completed undulators include two 5.0 cm period length, 89 period devices (U5.0s) which achieve a 0.85 T effective field at a 14 mm minimum gap and a 8.0 cm period length, 55 period device (U8.0) that reaches a 1.2 T effective field at a 14 mm minimum gap. The undulator under construction is a 10.0 cm period length, 43 period device (U10.0) that is designed to achieve 0.98 T at a 23 mm gap. Undulator magnetic gap variation (rms) is within 25 microns over the periodic structure length. Reproducibility of the adjustable magnetic gap has been measured to be within +/- 5 microns. Gap adjusting range is from 14 mm to 210 mm, which can be scanned in one minute. The 5.1 m long vacuum chambers are flat in the vertical direction to within 0.74 mm and straight in the horizontal direction to within 0.08 mm over the 4.6 m magnetic structure sections. Vacuum chamber base pressures after UHV beam conditioning are. in the mid 10-11 Torr range and storage ring operating pressures with full current are in the low 10-10 Torr range. Measurements show that the uncorrelated magnetic field errors are 0.23%, and 0.20% for the two U5.Os and the U8.0 respectively and that the field integrals are small over the 1 cm by 6 cm beam aperture. Device description, fabrication, and measurements are presented

  19. Tapered undulators for SASE FELs

    CERN Document Server

    Fawley, W M; Vinokurov, N A

    2002-01-01

    We discuss the use of tapered undulators to enhance the performance of free-electron lasers (FELs) based upon self-amplified spontaneous emission, where the radiation tends to have a relatively broad bandwidth and limited temporal coherence. Using the polychromatic FEL simulation code GINGER, we numerically demonstrate the effectiveness of tapered undulators for parameters corresponding to the Argonne low-energy undulator test line FEL and the proposed linac coherent light source.

  20. A flexible and testable software architecture: applying presenter first to a device server for the DOOCS accelerator control system of the European XFEL

    International Nuclear Information System (INIS)

    Presenter First (PF) uses a variant of Model View Presenter design pattern to add implementation flexibility and to improve testability of complex event-driven applications. It has been introduced in the context of GUI applications, but can easily be adapted to server applications. This paper describes how Presenter First methodology is used to develop a device server for the Programmable Logic Controls (PLC) of the European XFEL undulator systems, which are Windows PCs running PLC software from Beckhoff. The server implements a ZeroMQ message interface to the PLC allowing the DOOCS accelerator control system of the European XFEL to exchange data with the PLC by sending messages over the network. Our challenge is to develop a well-tested device server with a flexible architecture that allows integrating the server into other accelerator control systems like EPICS. (author)

  1. Conceptual design of an undulator system for a dedicated bio-imaging beamline at the European X-ray FEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2012-01-01

    We describe a future possible upgrade of the European XFEL consisting in the construction of an undulator beamline dedicated to life science experiments. The availability of free undulator tunnels at the European XFEL facility offers a unique opportunity to build a beamline optimized for coherent diffraction imaging of complex molecules, like proteins and other biologically interesting structures. Crucial parameters for such bio-imaging beamline are photon energy range, peak power, and pulse duration. Key component of the setup is the undulator source. The peak power is maximized in the photon energy range between 3 keV and 13 keV by the use of a very efficient combination of self-seeding, fresh bunch and tapered undulator techniques. The unique combination of ultra-high peak power of 1 TW in the entire energy range, and ultrashort pulse duration tunable from 2 fs to 10 fs, would allow for single shot coherent imaging of protein molecules with size larger than 10 nm. Also, the new beamline would enable imagin...

  2. Thermal Tests of Undulator Quad

    International Nuclear Information System (INIS)

    Running at the nominal temperature, the undulator quadrupole has a several degree temperature increase. This note describes the test used to determine the effect on the undulator integrals from the temperature gradient caused by the heat from the quadrupole conducting down the beam pipe. The undulator quadrupoles running at their nominal current of 4 amps heat up approximately 4 degrees Celsius; this magnet in turn heats up the beampipe which goes into the undulator. The heating ends up introducing a thermal gradient across the undulator which causes small changes in the magnetic field of the heated poles. By measuring the temperature change in the poles we can model the effects on the field and determine what the magnetic errors will be.

  3. Conceptual design of an undulator system for a dedicated bio-imaging beamline at the European X-ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2012-05-15

    We describe a future possible upgrade of the European XFEL consisting in the construction of an undulator beamline dedicated to life science experiments. The availability of free undulator tunnels at the European XFEL facility offers a unique opportunity to build a beamline optimized for coherent diffraction imaging of complex molecules, like proteins and other biologically interesting structures. Crucial parameters for such bio-imaging beamline are photon energy range, peak power, and pulse duration. Key component of the setup is the undulator source. The peak power is maximized in the photon energy range between 3 keV and 13 keV by the use of a very efficient combination of self-seeding, fresh bunch and tapered undulator techniques. The unique combination of ultra-high peak power of 1 TW in the entire energy range, and ultrashort pulse duration tunable from 2 fs to 10 fs, would allow for single shot coherent imaging of protein molecules with size larger than 10 nm. Also, the new beamline would enable imaging of large biological structures in the water window, between 0.3 keV and 0.4 keV. In order to make use of standardized components, at present we favor the use of SASE3-type undulator segments. The number segments, 40, is determined by the tapered length for the design output power of 1 TW. The present plan assumes the use of a nominal electron bunch with charge of 0.1 nC. Experiments will be performed without interference with the other three undulator beamlines. Therefore, the total amount of scheduled beam time per year is expected to be up to 4000 hours.

  4. Extension of SASE bandwidth up to 2% as a way to increase the efficiency of protein structure determination by x-ray nanocrystallography at the European XFEL

    CERN Document Server

    Serkez, Svitozar; Saldin, Evgeni; Zagorodnov, Igor; Geloni, Gianluca; Yefanov, Oleksander

    2013-01-01

    Femtosecond x-ray nanocrystallography exploiting XFEL radiation is an emerging method for protein structure determination using crystals with sizes ranging from a few tens to a few hundreds nanometers. Crystals are randomly hit by XFEL pulses, producing diffraction patterns at unknown orientations. One can determine these orientations by studying the diffraction patterns themselves, i.e. by indexing the Bragg peaks. The number of indexed individual images and the SASE bandwidth are inherently linked, because increasing the number of Bragg peaks per individual image requires increasing the bandwidth of the spectrum. This calls for a few percent SASE bandwidth, resulting in an increase in the number of indexed images at the same number of hits. Based on start-to-end simulations for the baseline of the European XFEL, we demonstrate here that it is possible to achieve up to a tenfold increase in SASE bandwidth, compared with the nominal mode of operation. This provides a route for further increasing the efficienc...

  5. Properties of undulator radiation

    International Nuclear Information System (INIS)

    Properties of the radiation emitted by a plane sinusoidal undulator are calculated in the far field approximation. Software has been developed to calculate the spectral distribution and polarization of the radiated intensity I(E) at a point on (or integrated over) a cross sectional observation plane of the photon beam. Spatial distribution of monochromatic radiation and power density contours are also calculated. Spectral broadening caused by an electron beam of finite spatial distribution is considered. Dispersive properties of the photon beam, including the dependence on deflection parameter, are analyzed. It is shown that reasonably constant intensity distribution I(E) can be obtained by properly shaping the beam acceptance aperture. 5 refs., 11 figs

  6. Grating monochromator for soft X-ray self-seeding the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

    2013-02-15

    Self-seeding is a promising approach to significantly narrow the SASE bandwidth of XFELs to produce nearly transform-limited pulses. The implementation of this method in the soft X-ray wavelength range necessarily involves gratings as dispersive elements. We study a very compact self-seeding scheme with a grating monochromator originally designed at SLAC, which can be straightforwardly installed in the SASE3 type undulator beamline at the European XFEL. The monochromator design is based on a toroidal VLS grating working at a fixed incidence angle mounting without entrance slit. It covers the spectral range from 300 eV to 1000 eV. The optical system was studied using wave optics method (in comparison with ray tracing) to evaluate the performance of the self-seeding scheme. Our wave optics analysis takes into account the actual beam wavefront of the radiation from the coherent FEL source, third order aberrations, and errors from each optical element. Wave optics is the only method available, in combination with FEL simulations, for the design of a self-seeding monochromator without exit slit. We show that, without exit slit, the self-seeding scheme is distinguished by the much needed experimental simplicity, and can practically give the same resolving power (about 7000) as with an exit slit. Wave optics is also naturally applicable to calculations of the self-seeding scheme efficiency, which include the monochromator transmittance and the effect of the mismatching between seed beam and electron beam. Simulations show that the FEL power reaches 1 TW and that the spectral density for a TW pulse is about two orders of magnitude higher than that for the SASE pulse at saturation.

  7. Development of vacuum components for the project of x-ray free electron laser (XFEL/SPring-8)

    International Nuclear Information System (INIS)

    Several new vacuum components have been developed for the XFEL/SPring-8 project. Vacuum waveguide flanges were successfully developed. These flanges provide both RF seal and vacuum seal. The vacuum seal mechanism of these flanges can make seal completely even with a deep scratch on the gasket. Solid-lubricated clean bolt and nut were developed for this flange to avoid organic dust pollution in the vacuum that induces RF discharge. A small RF contact for 28 mm inside diameter bellows was developed. This free ends structure RF contact can move freely in all directions and realize large displacement. The vacuum system of in-vacuum type undulator that commonly used in the accelerators is also described briefly. (author)

  8. Proposal for a scheme to generate 10 TW-level femtosecond x-ray pulses for imaging single protein molecules at the European XFEL

    CERN Document Server

    Serkez, Svitozar; Saldin, Evgeni; Zagorodnov, Igor; Geloni, Gianluca; Yefanov, Oleksander

    2013-01-01

    Single biomolecular imaging using XFEL radiation is an emerging method for protein structure determination using the "diffraction before destruction" method at near atomic resolution. Crucial parameters for such bio-imaging experiments are photon energy range, peak power, pulse duration, and transverse coherence. The largest diffraction signals are achieved at the longest wavelength that supports a given resolution, which should be better than 0.3 nm. We propose a configuration which combines self-seeding and undulator tapering techniques with the emittance-spoiler method in order to increase the XFEL output peak power and to shorten the pulse duration up to a level sufficient for performing bio-imaging of single protein molecules at the optimal photon energy range, i.e. around 4 keV. Experiments at the LCLS confirmed the feasibility of these three new techniques. Based on start-to-end simulations we demonstrate that self-seeding, combined with undulator tapering, allows one to achieve up to a 100-fold increa...

  9. Proposal for a scheme to generate 10 TW-Level femtosecond X-ray pulses for imaging single protein molecules at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Yefanov, Oleksander [Center for Free-Electron Laser Science, Hamburg (Germany)

    2013-06-15

    Single biomolecular imaging using XFEL radiation is an emerging method for protein structure determination using the ''diffraction before destruction'' method at near atomic resolution. Crucial parameters for such bio-imaging experiments are photon energy range, peak power, pulse duration, and transverse coherence. The largest diffraction signals are achieved at the longest wavelength that supports a given resolution, which should be better than 0.3 nm. We propose a configuration which combines self-seeding and undulator tapering techniques with the emittance-spoiler method in order to increase the XFEL output peak power and to shorten the pulse duration up to a level sufficient for performing bio-imaging of single protein molecules at the optimal photon energy range, i.e. around 4 keV. Experiments at the LCLS confirmed the feasibility of these three new techniques. Based on start-to-end simulations we demonstrate that self-seeding, combined with undulator tapering, allows one to achieve up to a 100-fold increase in peak-power. A slotted foil in the last bunch compressor is added for X-ray pulse duration control. Simulations indicate that one can achieve diffraction to the desired resolution with 50 mJ (corresponding to 10{sup 14} photons) per 10 fs pulse at 3.5 keV photon energy in a 100 nm focus. This result is exemplified using the photosystem I membrane protein as a case study.

  10. Proposal for a scheme to generate 10 TW-Level femtosecond X-ray pulses for imaging single protein molecules at the European XFEL

    International Nuclear Information System (INIS)

    Single biomolecular imaging using XFEL radiation is an emerging method for protein structure determination using the ''diffraction before destruction'' method at near atomic resolution. Crucial parameters for such bio-imaging experiments are photon energy range, peak power, pulse duration, and transverse coherence. The largest diffraction signals are achieved at the longest wavelength that supports a given resolution, which should be better than 0.3 nm. We propose a configuration which combines self-seeding and undulator tapering techniques with the emittance-spoiler method in order to increase the XFEL output peak power and to shorten the pulse duration up to a level sufficient for performing bio-imaging of single protein molecules at the optimal photon energy range, i.e. around 4 keV. Experiments at the LCLS confirmed the feasibility of these three new techniques. Based on start-to-end simulations we demonstrate that self-seeding, combined with undulator tapering, allows one to achieve up to a 100-fold increase in peak-power. A slotted foil in the last bunch compressor is added for X-ray pulse duration control. Simulations indicate that one can achieve diffraction to the desired resolution with 50 mJ (corresponding to 1014 photons) per 10 fs pulse at 3.5 keV photon energy in a 100 nm focus. This result is exemplified using the photosystem I membrane protein as a case study.

  11. Interferometry using undulator sources

    International Nuclear Information System (INIS)

    Optical systems for extreme ultraviolet (EUV) lithography need to use optical components with subnanometer surface figure error tolerances to achieve diffraction-limited performance [M.D. Himel, in Soft X-Ray Projection Lithography, A.M. Hawryluk and R.H. Stulen, eds. (OSA, Washington, D.C., 1993), 18, 1089, and D. Attwood et al., Appl. Opt. 32, 7022 (1993)]. Also, multilayer-coated optics require at-wavelength wavefront measurement to characterize phase effects that cannot be measured by conventional optical interferometry. Furthermore, EUV optical systems will additionally require final testing and alignment at the operational wavelength for adjustment and reduction of the cumulative optical surface errors. Therefore, at-wavelength interferometric measurement of EUV optics will be the necessary metrology tool for the successful development of optics for EUV lithography. An EUV point diffraction interferometer (PDI) has been developed at the Center for X-Ray Optics (CXRO) and has been already in operation for a year [K. Goldberg et al., in Extreme Ultra Lithography, D.T. Attwood and F. Zernike, eds. (OSA, Washington, D.C., 1994), K. Goldberg et al., Proc. SPIE 2437, to be published, and K. Goldberg et al., J. Vac. Sci. Technol. B 13, 2923 (1995)] using an undulator radiation source and coherent optics beamline at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. An overview of the PDI interferometer and some EUV wavefront measurements obtained with this instrument will be presented. In addition, future developments planned for EUV interferometry at CXRO towards the measurement of actual EUV lithography optics will be shown. copyright 1996 American Institute of Physics

  12. Multi-Bunch Beam Dynamics Studies for the European XFEL

    CERN Document Server

    Baboi, N

    2004-01-01

    In the X-ray free electron laser planned to be built at DESY (TESLA XFEL) the acceleration of the electron bunches will be made with 9-cell superconducting cavities. These cavities have been initially developed within the TESLA linear collider study. The impact of the higher order modes (HOM) has been shown to be within the acceptable beam dynamics limits for the collider. For the XFEL the dynamics is relaxed from point of view of multi-bunch effects (e.g. shorter length, higher emittance). However the lower energy and different time structure of the beam make the study of the HOM effects in the XFEL linac necessary. Multi-bunch beam dynamics studies are ongoing. The results of the HOM measurements at the TESLA Test Facility are used. Several options for the beam structure, as necessary for various applications, are studied. The results will be discussed.

  13. The properties of undulator radiation

    International Nuclear Information System (INIS)

    A new generation of synchrotron radiation light sources covering the VUV, soft x-ray, and hard x-ray spectral regions is under construction in several countries. These sources are designed specifically to use periodic magnetic undulators and low-emittance electron or positron beams to produce high-brightness near-diffraction-limited synchrotron radiation beams. Some of the novel features of the new sources are discussed, along with the characteristics of the radiation produced, with emphasis on the Advanced Light Source, a third-generation 1.5 GeV storage ring optimized for undulator use. A review of the properties of undulator radiation is presented, followed by a discussion of some of the unique challenges being faced by the builders and users of the new undulator sources. These include difficult mechanical and magnetic tolerance limits, a complex interaction with the storage ring, high x-ray beam power, partial coherence, harmonics, optics contamination, and the unusual spectral and angular properties of undulator radiation

  14. Visa undulator fiducialization and alignment

    International Nuclear Information System (INIS)

    As part of the R and D program towards a fourth generation light source, a Self-Amplified Spontaneous Emission (SASE) demonstration is being prepared. The Visible-Infrared SASE Amplifier (VISA) undulator will be installed at Brookhaven National Laboratory by the end of the year. The VISA undulator is an in-vacuum, 4-meter long, 1.8 cm period, pure-permanent magnet device, with a novel, strong focusing, permanent magnet FODO array included within the fixed, 6 mm undulator gap. The undulator is constructed of 99 cm long segments. To attain maximum SASE gain requires establishing overlap of electron and photon beams to within 50 μm rms. This imposes challenging tolerances on mechanical fabrication and magnetic field quality, and necessitates use of laser straightness interferometry for calibration and alignment of the magnetic axes of the undulator segments. This paper describes the magnetic centerline determination, and the fiducialization and alignment processes which were performed to meet the tolerance goal. (authors)

  15. Detector Development for the European XFEL: Requirements and Status

    CERN Document Server

    Koch, Andreas; Sztuk-Dambietz, Jolanta; Turcato, Monica

    2012-01-01

    The variety of applications and especially the unique European XFEL time structure will require adequate instrumentation to be developed to exploit the full potential of the light source. Two-dimensional integrating X-ray detectors with ultra-fast read out up to 4.5 MHz for 1024 x 1024 pixel images are under development for a variety of imaging applications. The actual status of the European XFEL detector development projects is presented. Furthermore, an outlook will be given with respect to detector research and development, performance optimization, integration, and commissioning.

  16. Status of detector development for the European XFEL

    CERN Document Server

    Sztuk-Dambietz, Jolanta; Koch, Andreas; Kuster, Markus; Turcato, Monica

    2013-01-01

    The European X-ray Free Electron Laser (XFEL.EU) will provide as-yet-unrivaled peak brilliance and ultra-short pulses of spatially coherent X-rays with a pulse length of less than 100 fs in the energy range between 0.25 and 25 keV. The high radiation intensity and ultra-short pulse duration will open a window for novel scientific techniques and will allow to explore new phenomena in biology, chemistry, material science, as well as matter at high energy density, atomic, ion and molecular physics. The variety of scientific applications and especially the unique XFEL.EU time structure require adequate instrumentation to be developed in order to exploit the full potential of the light source. To make optimal use of the unprecedented capabilities of the European XFEL and master these vast technological challenges, the European XFEL GmbH has started a detector R&D program. The technology concepts of the detector system presently under development are complementary in their performance and will cover the require...

  17. Extension of SASE bandwidth up to 2% as a way to increase the efficiency of protein structure determination by X-ray nanocrystallography at the European XFEL

    International Nuclear Information System (INIS)

    Femtosecond x-ray nanocrystallography exploiting XFEL radiation is an emerging method for protein structure determination using crystals with sizes ranging from a few tens to a few hundreds nanometers. Crystals are randomly hit by XFEL pulses, producing diffraction patterns at unknown orientations. One can determine these orientations by studying the diffraction patterns themselves, i.e. by indexing the Bragg peaks. The number of indexed individual images and the SASE bandwidth are inherently linked, because increasing the number of Bragg peaks per individual image requires increasing the bandwidth of the spectrum. This calls for a few percent SASE bandwidth, resulting in an increase in the number of indexed images at the same number of hits. Based on start-to-end simulations for the baseline of the European XFEL, we demonstrate here that it is possible to achieve up to a tenfold increase in SASE bandwidth, compared with the nominal mode of operation. This provides a route for further increasing the efficiency of protein structure determination at the European XFEL.We illustrate this concept with simulations of lysozyme nanocrystals.

  18. Extension of SASE bandwidth up to 2% as a way to increase the efficiency of protein structure determination by X-ray nanocrystallography at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gelonib, Gianluca [European XFEL GmbH, Hamburg (Germany); Yefanov, Oleksandr [Center for Free-Electron Laser Science, Hamburg (Germany)

    2013-06-15

    Femtosecond x-ray nanocrystallography exploiting XFEL radiation is an emerging method for protein structure determination using crystals with sizes ranging from a few tens to a few hundreds nanometers. Crystals are randomly hit by XFEL pulses, producing diffraction patterns at unknown orientations. One can determine these orientations by studying the diffraction patterns themselves, i.e. by indexing the Bragg peaks. The number of indexed individual images and the SASE bandwidth are inherently linked, because increasing the number of Bragg peaks per individual image requires increasing the bandwidth of the spectrum. This calls for a few percent SASE bandwidth, resulting in an increase in the number of indexed images at the same number of hits. Based on start-to-end simulations for the baseline of the European XFEL, we demonstrate here that it is possible to achieve up to a tenfold increase in SASE bandwidth, compared with the nominal mode of operation. This provides a route for further increasing the efficiency of protein structure determination at the European XFEL.We illustrate this concept with simulations of lysozyme nanocrystals.

  19. APS undulator radiation: First results

    International Nuclear Information System (INIS)

    The first undulator radiation has been extracted from the Advanced Photon Source (APS). The results from the characterization of this radiation are very satisfactory. With the undulator set at a gap of 15.8 mm (K=1.61), harmonics as high as the 17th were observed using a crystal spectrometer. The angular distribution of the third-harmonic radiation was measured, and the source was imaged using a zone plate to determine the particle beam emittance. The horizontal beam emittance was found to be 6.9 ± 1.0 nm-rad, and the vertical emittance coupling was found to be less than 3%. The absolute spectral flux was measured over a wide range of photon energies, and it agrees remarkably well with the theoretical calculations based on the measured undulator magnetic field profile and the measured beam emittance. These results indicate that both the emittance of the electron beam and the undulator magnetic field quality exceed the original specifications

  20. Transition undulator radiation as bright infrared sources

    International Nuclear Information System (INIS)

    Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/γ, where γ is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron's longitudinal velocity as it enters and leaves the undulator. The characteristics of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets

  1. Transition undulator radiation as bright infrared sources

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.J. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/{gamma}, where {gamma} is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron`s longitudinal velocity as it enters and leaves the undulator. The characteristic of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets.

  2. Damping Undulators vs Damping Wigglers

    OpenAIRE

    Muchnoi, Nickolai

    2016-01-01

    Use of damping wigglers is a common technique for beam emittance reduction in the electron storage rings. The general approach to estimate damping effect is based on evaluation of several radiation integrals for a storage ring itself as well as for insertion devices. In this letter we show that a wiggler radiation integrals should be tweaked to account for the impact of lower harmonics of undulator radiation, which is an equivalent of Thomson scattering. Under certain conditions, these amendm...

  3. EIROforum welcomes the European XFEL as a new member

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    The European research facility XFEL has become the eighth member of EIROforum. Just as political and economic interests have become unified within Europe, scientific research is benefiting from a similar alliance.   Massimo Altarelli, Chairman of the XFEL Management Board (left) and Francesco Romanelli, Chairman of the EIROforum (right). In the back (left to right): Francesco Sette (ESRF), Felicitas Pauss (CERN), Iain Mattaj (EMBL), Richard Wagner (ILL), Rowena Sirey (ESO) and David Southwood (ESA). In this day and age, scientific research is oriented towards large-scale projects, which require the involvement of a large number of partners – meaning funding institutes or national governments – and, obviously, the cooperation of the leading experts in a variety of related fields. For these reasons, it is essential to encourage synergies on an international level, combining resources, facilities and expertise. This is the quest of EIROforum, which brings together research organ...

  4. X-ray imaging detectors for synchrotron and XFEL sources

    OpenAIRE

    Takaki Hatsui; Heinz Graafsma

    2015-01-01

    Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL) experiments provide high-frame-rate integrating detectors with both high sensitivit...

  5. Proposed continuous wave energy recovery operation of an XFEL

    Energy Technology Data Exchange (ETDEWEB)

    J. Sekutowicz; S. A. Bogacz; D. Douglas; P. Kneisel; G. P. Williams; M. Ferrario; L. Serafini; I. Ben-Zvi; J. Rose; J. Smedley; T. Srinivasan-Rao; W.-D. Moeller; B. Petersen; D. Proch; S. Simrock; P. Colestock; J. B. Rosenzweig

    2004-05-01

    Commissioning of two large coherent light facilities at SLAC and DESY should begin in 2008 and in 2011 respectively. In this paper we look further into the future, hoping to answer, in a very preliminary way, two questions. First: ''What will the next generation of XFEL facilities look like?'' Believing that superconducting technology offers advantages such as high quality beams with highly populated bunches, the possibility of energy recovery and higher overall efficiency than warm technology, we focus this preliminary study on the superconducting option. From this belief the second question arises: ''What modifications in superconducting technology and in the machine design are needed, as compared to the present DESY XFEL, and what kind of R&D program should be proposed to arrive in the next few years at a technically feasible solution with even higher brilliance and increased overall conversion of AC power to photon beam power?'' In this paper we will very often refer to and profit from the DESY XFEL design, acknowledging its many technically innovative solutions.

  6. Continuous wave energy recovery operation of an XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Jacek Sekutowicz; S. A. Bogacz; D. Douglas; Peter Kneisel; G. P. Williams; M. Ferrario; L. Serafini; I. Ben-Zvi; J. Rose; T. Srinivasan-Rao; W.-D. Mueller; B. Petersen; D. Proch; S.Simrock; P. Colestock; J. B. Rosenzweig

    2003-12-01

    Commissioning of two large coherent light facilities at SLAC and DESY should begin in 2008 and in 2011 respectively. In this paper we look further into the future, hoping to answer, in a very preliminary way, two questions. First: ''What will the next generation of XFEL facilities look like?'' Believing that superconducting technology offers advantages such as high quality beams with highly populated bunches, the possibility of energy recovery and higher overall efficiency than warm technology, we focus this preliminary study on the superconducting option. From this belief the second question arises: ''What modifications in superconducting technology and in the machine design are needed, as compared to the present DESY XFEL, and what kind of R&D program should be proposed to arrive in the next few years at a technically feasible solution with even higher brilliance and increased overall conversion of AC power to photon beam power?'' In this paper we will very often refer to and profit from the DESY XFEL design, acknowledging its many technically innovative solutions.

  7. Numerical Simulations of X-Ray Free Electron Lasers (XFEL)

    KAUST Repository

    Antonelli, Paolo

    2014-11-04

    We study a nonlinear Schrödinger equation which arises as an effective single particle model in X-ray free electron lasers (XFEL). This equation appears as a first principles model for the beam-matter interactions that would take place in an XFEL molecular imaging experiment in [A. Fratalocchi and G. Ruocco, Phys. Rev. Lett., 106 (2011), 105504]. Since XFEL are more powerful by several orders of magnitude than more conventional lasers, the systematic investigation of many of the standard assumptions and approximations has attracted increased attention. In this model the electrons move under a rapidly oscillating electromagnetic field, and the convergence of the problem to an effective time-averaged one is examined. We use an operator splitting pseudospectral method to investigate numerically the behavior of the model versus that of its time-averaged version in complex situations, namely the energy subcritical/mass supercritical case and in the presence of a periodic lattice. We find the time-averaged model to be an effective approximation, even close to blowup, for fast enough oscillations of the external field. This work extends previous analytical results for simpler cases [P. Antonelli, A. Athanassoulis, H. Hajaiej, and P. Markowich, Arch. Ration. Mech. Anal., 211 (2014), pp. 711--732].

  8. Damping Undulators vs Damping Wigglers

    CERN Document Server

    Muchnoi, Nickolai

    2016-01-01

    Use of damping wigglers is a common technique for beam emittance reduction in the electron storage rings. The general approach to estimate damping effect is based on evaluation of several radiation integrals for a storage ring itself as well as for insertion devices. In this letter we show that a wiggler radiation integrals should be tweaked to account for the impact of lower harmonics of undulator radiation, which is an equivalent of Thomson scattering. Under certain conditions, these amendments play a decisive role in a formation of equilibrium emittance.

  9. RF system modeling and controller design for the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Christian

    2011-06-15

    The European XFEL is being constructed at the Deutsche Elektronen Synchrotron DESY to generate intense, ultrashort pulses of highly coherent and monochromatic X-Rays for material science research. X-ray flashes are generated by accelerating electron bunches within superconducting cavities with radio frequency (RF) fields to energies up to 17.5 GeV. The digital control of these fields requires extremely high quality in order to achieve the physical processes of photon generation. DESY offers with FLASH a pilot test facility, allowing to test and develop most necessary components, even before the XFEL is conducted. Current field control is based on a proportional feedback controller in addition to a constant feedforward drive, which do not meet the high requirements of the XFEL. This thesis shows that a model based controller design can achieve the necessary field regulation requirements. A linear, time invariant ''black box model'' is estimated, which characterizes the essential dynamic behavior. This model is not based on physical assumptions, but describes exclusively the transfer behavior of the plant. The acceleration modules are operated in a pulsed mode, in which the RF field must be kept constant for a finite period. The character of the disturbances and variations from pulse-to-pulse, together with the properties of the system, require a combination of controlled feedforward drive and feedback. Generally unpredictable, low frequency pulse-to-pulse variations are suppressed by the feedback controller. The structural design of the complex multivariable feedback controller is given, which constrains the model based design approach to assign the controller parameters only. Estimation of the parameters, which can not be tuned manually, is done by the method of H{sub {infinity}} loop shaping which is often applied in modern control theory. However, disturbances within a pulse are in a high frequency range concerning the short pulse duration

  10. Way to increase the user access at the LCLS baseline

    International Nuclear Information System (INIS)

    Although the LCLS photon beam is meant for a single user, the baseline undulator is long enough to serve two users simultaneously. To this end, we propose a setup composed of two simple elements: an X-ray mirror pair for X-ray beam deflection, and a short (4 m-long) magnetic chicane, which creates an offset for mirror pair installation in the middle of the baseline undulator. The insertable mirror pair can be used for spatial separation of the X-ray beams generated in the first and in the second half of the baseline undulator. The method of deactivating one half and activating another half of the undulator is based on the rapid switching of the FEL amplification process. As proposed elsewhere, using a kicker installed upstream of the LCLS baseline undulator and an already existing corrector in the first half of the undulator, it is possible to rapidly switch the X-ray beam from one user to another, thus providing two active beamlines at any time. We present simulation results dealing with the LCLS baseline, and show that it is possible to generate two saturated SASE X-ray beams in the whole 0.8-8 keV photon energy range in the same baseline undulator. These can be exploited to serve two users. Implementation of the proposed technique does not perturb the baseline mode of operation of the LCLS undulator. Moreover, the magnetic chicane setup is very flexible, and can be used as a self-seeding setup too. We present simulation results for the LCLS baseline undulator with SHAB (second harmonic afterburner) and show that one can produce monochromatic radiation at the 2nd harmonic as well as at the 1st. We describe an efficient way for obtaining multi-user operation at the LCLS hard X-ray FEL. To this end, a photon beam distribution system based on the use of crystals in the Bragg reflection geometry is proposed. The reflectivity of crystal deflectors can be switched fast enough by flipping the crystals with piezoelectric devices similar to those for X-ray phase retarders

  11. Design of the AGIPD Sensor for the European XFEL

    CERN Document Server

    Schwandt, J; Klanner, R; Zhang, J

    2012-01-01

    For experiments at the European X-Ray Free-Electron Laser (XFEL) the Adaptive Gain Integrating Pixel Detector (AGIPD) is under development. The particular requirements for the detector are a high dynamic range of 0, 1 - to more than 10E4 12.4 keV photons per pixel within an XFEL pulse duration of < 100 fs, and a radiation tolerance of doses up to 1 GGy for 3 years of operation. The detector will have 1024 x 1024 p+ pixels with a pixel size of 200 um x 200 um and will be manufactured on 500 um thick n-type silicon. The design value for the operating voltage is 500 V, however, for special applications an operation up to ~ 1000 V should be possible. Experimental data on the dose dependence of the surface density of oxide charges at the Si-SiO2 interface and the surface-current density have been implemented in the SYNOPSYS TCAD simulation program in order to optimize the design of the pixel and guard-ring layout. The methodology of the sensor design, the optimization of the most relevant parameters and the lay...

  12. High harmonic generation in undulators for FEL

    Science.gov (United States)

    Zhukovsky, K.

    2016-02-01

    The analytical study of the undulator radiation (UR), accounting for major sources of the spectral line broadening is presented. Analytical expressions for the UR spectrum and intensity are obtained. They demonstrate possibilities of the compensation of the divergency by the constant magnetic component. Some examples of single and double frequency undulators are considered. Generation of harmonics is studied with account for homogeneous and inhomogeneous broadening in real devices. The obtained results with account for all broadening sources are applied for evaluation of free electron laser (FEL) performance and compared with those, obtained with the ideal undulator.

  13. Undulator with dynamic compensation of magnetic forces

    Energy Technology Data Exchange (ETDEWEB)

    Gluskin, Efim; Trakhtenberg, Emil; Xu, Joseph Z.

    2016-05-31

    A method and apparatus for implementing dynamic compensation of magnetic forces for undulators are provided. An undulator includes a respective set of magnet arrays, each attached to a strongback, and placed on horizontal slides and positioned parallel relative to each other with a predetermined gap. Magnetic forces are compensated by a set of compensation springs placed along the strongback. The compensation springs are conical springs having exponential-force characteristics that substantially match undulator magnetic forces independently of the predetermined gap. The conical springs are positioned along the length of the magnets.

  14. Measurement and Optimization of the VISA Undulator

    International Nuclear Information System (INIS)

    The Visible-Infrared SASE Amplifier (VISA) undulator is an in-vacuum, 4-meter long, 1.8 cm period, pure-permanent magnet device, with a novel, strong focusing, permanent magnet FODO array included within the fixed, 6 mm undulator gap. The undulator magnet is constructed of 99-cm long segments, joined into a continuous structure. To attain maximum SASE gain requires establishing overlap of electron and photon beams to within 50 microns rms. This imposes challenging tolerances on mechanical fabrication and magnetic field quality, and necessitates use of laser straightness interferometry for calibration and alignment of the magnetic axes of the undulator segments. This paper describes the computerized magnet sorting, pulsed-wire magnetic measurements, trajectory shimming and magnetic axis calibration performed to meet this goal

  15. Experience with small-gap undulators

    International Nuclear Information System (INIS)

    Over the past year, we have gained some experience with small-gap undulators through operation of the NSLS Prototype Small-Gap Undulator (PSGU). PSGU is a small R ampersand D insertion device intended for investigation of the fundamental limitations of small-gap devices. At the same time, PSGU aptly demonstrates the enhanced performance offered by such devices, through generation of radiation with a 16 mm period pure-permanent-magnet undulator. In what follows, we present a brief description of PSGU and a summary of operating experience to date. This includes a spectrum of the undulator radiation produced at a 5.6 mm magnet gap, and the appearance of operational limitations, namely lifetime degradation, beam instabilities, and increased bremsstrahlung radiation

  16. Algorithms to Automate LCLS Undulator Tuning

    International Nuclear Information System (INIS)

    Automation of the LCLS undulator tuning offers many advantages to the project. Automation can make a substantial reduction in the amount of time the tuning takes. Undulator tuning is fairly complex and automation can make the final tuning less dependent on the skill of the operator. Also, algorithms are fixed and can be scrutinized and reviewed, as opposed to an individual doing the tuning by hand. This note presents algorithms implemented in a computer program written for LCLS undulator tuning. The LCLS undulators must meet the following specifications. The maximum trajectory walkoff must be less than 5 (micro)m over 10 m. The first field integral must be below 40 x 10-6 Tm. The second field integral must be below 50 x 10-6 Tm2. The phase error between the electron motion and the radiation field must be less than 10 degrees in an undulator. The K parameter must have the value of 3.5000 ± 0.0005. The phase matching from the break regions into the undulator must be accurate to better than 10 degrees. A phase change of 113 x 2π must take place over a distance of 3.656 m centered on the undulator. Achieving these requirements is the goal of the tuning process. Most of the tuning is done with Hall probe measurements. The field integrals are checked using long coil measurements. An analysis program written in Matlab takes the Hall probe measurements and computes the trajectories, phase errors, K value, etc. The analysis program and its calculation techniques were described in a previous note. In this note, a second Matlab program containing tuning algorithms is described. The algorithms to determine the required number and placement of the shims are discussed in detail. This note describes the operation of a computer program which was written to automate LCLS undulator tuning. The algorithms used to compute the shim sizes and locations are discussed.

  17. A preliminary design of a knot undulator.

    Science.gov (United States)

    Xi, Fuchun; Shi, Tan; Fan, Qingyan; Prestemon, Soren; Wan, Weishi; An, Zhenghua; Qiao, S

    2013-01-01

    The magnetic field configuration of the previously proposed knot undulator [Qiao et al. (2009). Rev. Sci. Instrum. 80, 085108] is realised in the design of a hybridized elliptically polarized undulator, which is presented. Although the details of the field distribution are not the same as those in the theoretical proposal, it is demonstrated that the practical knot undulator could work perfectly. In order to understand the minor discrepancies of the two, mathematical formulae of the synchrotron radiation are derived based on the Fourier transform of the magnetic field. From the results of calculations by simulation program, the discrepancies could be well interpreted by the corresponding formulae. The results show the importance of optimization of the end sections of the knot undulator to suppress the on-axis heat load. Furthermore, a study of the impact of the undulator on beam dynamics of the storage ring was conducted using the Shanghai Synchrotron Radiation Facility as an example and the results show that the knot undulator has little effect on the beam. PMID:23254667

  18. A pump-probe XFEL particle injector for hydrated samples

    CERN Document Server

    Weierstall, U; Spence, J C H

    2011-01-01

    We have developed a liquid jet injector system that can be used for hydrated sample delivery at X-ray Free Electron Laser (XFEL) sources and 3rd generation synchrotron sources. The injector is based on the Gas Dynamic Virtual Nozzle (GDVN), which generates a liquid jet with diameter ranging from 300 nm to 20 {\\mu}m without the clogging problems associated with conventional Rayleigh jets. An improved nozzle design is presented here. A differential pumping system protects the vacuum chamber and an in-vacuum microscope allows observation of the liquid jet for diagnostics while it is being exposed to the X-ray beam. A fiber optically coupled pump laser illuminating the jet is incorporated for pump-probe experiments. First results with this injector system have been obtained at the LCLS.

  19. Absorbed XFEL dose in the components of the LCLS X-Ray Optics

    Energy Technology Data Exchange (ETDEWEB)

    Hau-Riege, S

    2005-09-27

    We list the materials that are anticipated to be placed into the Linac Coherent Light Source (LCLS) x-ray free electron laser (XFEL) beam line, their positions, and the absorbed dose, and compare this dose with anticipated damage thresholds.

  20. A New PLS-II In-Vacuum Undulator and Characterization of Undulator Radiation

    CERN Document Server

    Kim, D-E; Park, K-H; Seo, H-S; Ha, T; Jeong, Y-G; Han, H-S; Lee, W W; Huang, J-Y; Nam, S; Kim, K-R; Shin, S

    2016-01-01

    This paper describes the result of overall studies from development to characterization of undulator radiation. After three years of upgrading, PLS-II [1, 2] has been operating successfully since 21st March 2012. During the upgrade, we developed and installed an in-vacuum undulator (IVU) that generates brilliant X-ray beam. The IVU with 3 GeV electron beam generates undulator radiation up to ~ 21 keV using 11th higher harmonic. The characterizations of the undulator radiation at an X-ray beam line in PLS-II agreed well with the simulation. Based on this performance demonstration, the in-vacuum undulator is successfully operating at PLS-II.

  1. Emittance Measurements of the Electron Beam at PITZ for the Commissioning Phase of the European XFEL

    OpenAIRE

    Vashchenko, G.; Asova, G.; Khojoyan, M; Kourkafas, G.; Kraslinikov, M.; Malyutin, D.; Melkumyan, D.; Oppelt, A.; Otevrel, M.; Renier, Y.; Rublack, T.; Stephan, F.; Bakr, M.; Zhao, Q.; Lishilin, O.

    2015-01-01

    For the operation of free electron lasers (FELs) like the European XFEL and FLASH located at DESY, Hamburg Site,high quality electron beams are required already from the source. The Photo Injector Test facility at DESY, ZeuthenSite (PITZ), was established to develop, characterize and optimize electron sources for such FELs. Last year the workat PITZ focused on the optimization of a photo injector operated very close to the startup parameters of the EuropeanXFEL. This implies photocathode lase...

  2. Coherent Radiation Effects in the LCLS Undulator

    International Nuclear Information System (INIS)

    For X-ray Free-Electron Lasers such as LCLS and TESLA FEL, a change in the electron energy while amplifying the FEL radiation can shift the resonance condition out of the bandwidth of the FEL. The largest sources of energy loss is the emission of incoherent undulator radiation. Because the loss per electron depends only on the undulator parameters and the beam energy, which are fixed for a given resonant wavelength, the average energy loss can be compensated for by a fixed taper of the undulator. Coherent radiation has a strong enhancement proportional to the number of electrons in the bunch for frequencies comparable to or longer than the bunch dimension. If the emitted coherent energy becomes comparable to that of the incoherent emission, it has to be included in the taper as well. However, the coherent loss depends on the bunch charge and the applied compression scheme and a change of these parameters would require a change of the taper. This imposes a limitation on the practical operation of Free-Electron Lasers, where the taper can only be adjusted manually. In this presentation we analyze the coherent emission of undulator radiation and transition undulator radiation for LCLS, and estimate whether the resulting energy losses are significant for the operation of LCLS.

  3. NSLS prototype small-gap undulator (PSGU)

    International Nuclear Information System (INIS)

    The NSLS Prototype Small-Gap Undulator (PSGU) will serve as a tool to study lifetime degradation and the onset of beam instabilities as the beam duct aperture is decreased. The device will consist of variable-gap vacuum vessel had a permanent magnet undulator, with independent magnet-gap control. The vacuum vessel design attempts to minimize both residual gas pressures and beam impedances. The undulator will be 320 mm long and utilizes a pure-permanent-magnet structure with 6 blocks per 16 mm period. For a nominal operating aperture of 4 mm, PSGU will produce a peak brightness in the fundamental and third harmonic of 7 x 1016 and 1 x 1016 photons sm-bullet sec-1 sm-bullet mrad-2mm-2 sm-bullet(0.1% BW)-1 at photon energies of 2.5 keV and 7.5 keV, respectively. 5 refs., 3 figs., 2 tabs

  4. Experimental characterization of ALS undulator radiation

    International Nuclear Information System (INIS)

    The radiation from the 5 cm period undulator at the Advanced Light Source (ALS) has been characterized using a transmission grating spectrometer. Spectral and angular distributions of radiation were measured for deflection parameter K values between 0.45 and 2.12 at low storage ring current (0.1--0.5 mA). From the calibration of the spectrometer, the absolute flux density of the undulator harmonics has been determined together with the spectral linewidth. The electron the beam emittance was determined by analyzing the angular distribution of the red-shifted fundamental. Comparison has been made with radiation calculations based upon the measured magnetic field data of the undulator. Including field errors, electron beam emittance and energy spread, good agreement is found between theoretically and experimentally determined harmonic widths and peak brightness

  5. Optical Fibre Dosimeter for SASE FEL Undulators

    CERN Document Server

    Körfer, M

    2003-01-01

    Single pass Free Electron Lasers (FELs) based on self-amplified spontaneous emission (SASE) are developed for high brightness and short wavelength applications. They use permanent magnet undulators which are radiation sensitive devices. During accelerator commissioning beam losses can appear anywhere along the undulator line. To avoid damage of the permanent magnets due to radiation, an optical fibre dosimeter system can be used. The increase of absorption caused by ionizing radiation is measured in radiation sensitive optical fibers. The dose system enables relatively fast particle loss tuning during accelerator operation and allows the monitoring of the accumulated dose. Dose measurements in narrow gaps which are inaccessible for any other (online) dosimeter type become possible. The electromagnetic insensitivity of optical fibre sensor is an advantage of applications in strong magnetic undulator fields. At each location the light absorption is measured by using an optical power-meter. The dynamic range is ...

  6. Field Optimization for short Period Undulators

    CERN Document Server

    Peiffer, P; Rossmanith, R; Schoerling, D

    2011-01-01

    Undulators dedicated to low energy electron beams, like Laser Wakefield Accelerators, require very short period lengths to achieve X-ray emission. However, at these short period length (LambdaU ~ 5 mm) it becomes difficult to reach magnetic field amplitudes that lead to a K parameter of >1, which is generally desired. Room temperature permanent magnets and even superconductive undulators using Nb-Ti as conductor material have proven insufficient to achieve the desired field amplitudes. The superconductor Nb3Sn has the theoretical potential to achieve the desired fields. However, up to now it is limited by several technological challenges to much lower field values than theoretically predicted. An alternative idea for higher fields is to manufacture the poles of the undulator body from Holmium instead of iron or to use Nb-Ti wires with a higher superconductor/copper ratio. The advantages and challenges of the different options are compared in this contribution.

  7. Canonical particle tracking in undulator fields

    International Nuclear Information System (INIS)

    A new algebraic mapping routine for particle tracking across wiggler and undulator fields in presented. It is based on a power series expansion of the generating function to guarantee fully canonical transformations. This method is 10 to 100 times faster than integration routines, applied in tracking codes like BETA or RACETRACK. The tracking method presented is not restricted to wigglers and undulators, it can be applied to other magnetic fields as well such as fringing fields of quadrupoles or dipoles if the suggested expansion converges

  8. Integrated Detector Control and Calibration Processing at the European XFEL

    CERN Document Server

    Münnich, A; Heisen, B C; Januschek, F; Kuster, M; Lang, P M; Raab, N; Rüter, T; Sztuk-Dambietz, J; Turcato, M

    2016-01-01

    The European X-ray Free Electron Laser is a high-intensity X-ray light source currently being constructed in the area of Hamburg, that will provide spatially coherent X-rays in the energy range between $0.25\\,\\mathrm{keV}$ and $25\\,\\mathrm{keV}$. The machine will deliver $10\\,\\mathrm{trains/s}$, consisting of up to $2700\\,\\mathrm{pulses}$, with a $4.5\\,\\mathrm{MHz}$ repetition rate. The LPD, DSSC and AGIPD detectors are being developed to provide high dynamic-range Mpixel imaging capabilities at the mentioned repetition rates. A consequence of these detector characteristics is that they generate raw data volumes of up to $15\\,\\mathrm{Gbyte/s}$. In addition the detector's on-sensor memory-cell and multi-/non-linear gain architectures pose unique challenges in data correction and calibration, requiring online access to operating conditions and control settings. We present how these challenges are addressed within XFEL's control and analysis framework Karabo, which integrates access to hardware conditions, acqui...

  9. Undulator Radiation Damage Experience at LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Nuhn, H. D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Field, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Mao, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Levashov, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Santana, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Welch, J. N. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wolf, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-01-06

    The SLAC National Accelerator Laboratory has been running the Linac Coherent Light Source (LCLS), the first x-ray Free Electron Laser since 2009. Undulator magnet damage from radiation, produced by the electron beam traveling through the 133-m long straight vacuum tube, has been and is a concern. A damage measurement experiment has been performed in 2007 in order to obtain dose versus damage calibrations. Radiation reduction and detection devices have been integrated into the LCLS undulator system. The accumulated radiation dose rate was continuously monitored and recorded. In addition, undulator segments have been routinely removed from the beamline to be checked for magnetic (50 ppm, rms) and mechanic (about 0.25 µm, rms) changes. A reduction in strength of the undulator segments is being observed, at a level, which is now clearly above the noise. Recently, potential sources for the observed integrated radiation levels have been investigated. The paper discusses the results of these investigation as well as comparison between observed damage and measured dose accumulations and discusses, briefly, strategies for the new LCLS-II upgrade, which will be operating at more than 300 times larger beam rate.

  10. KIAE-1.5-3 undulator performance

    Energy Technology Data Exchange (ETDEWEB)

    Varfolomeev, A.A.; Ivanchenko, S.N.; Khlebnikov, A.S. [Kurchatov Institute, Moscow (Russian Federation)] [and others

    1995-12-31

    Hybrid type undulator with 60 periods of {lambda}{sub w} = 1.5 cm and tunable gap in wide range has been designed and manufactured. Additional side magnet arrays provide high magnetic field (near Halbach limit) along with transverse field profiles for e.b. focusing.

  11. Generation and characterization of superradiant undulator radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bocek, D.

    1997-06-01

    High-power, pulsed, coherent, far-infrared (FIR) radiation has many scientific applications, such as pump-probe studies of surfaces, liquids, and solids, studies of high-T{sub c} superconductors, biophysics, plasma diagnostics, and excitation of Rydberg atoms. Few sources of such FIR radiation currently exist. Superradiant undulator radiation produced at the SUNSHINE (Stanford UNiversity SHort INtense Electron-source) is such a FIR source. First proposed in the mm-wave spectral range by Motz, superradiant undulator radiation has been realized in the 45 {micro}m to 300 {micro}m spectral range by using sub-picosecond electron bunches produced by the SUNSHINE facility. The experimental setup and measurements of this FIR radiation are reported in this thesis. In addition, to being a useful FIR source, the superradiant undulator radiation produced at SUNSHINE is an object of research in itself. Measured superlinear growth of the radiated energy along the undulator demonstrates the self-amplification of radiation by the electron bunch. This superlinear growth is seen at 47 {micro}m to 70 {micro}m wavelengths. These wavelengths are an order of magnitude shorter than in previous self-amplification demonstrations.

  12. Status and commissioning results of the helium refrigerator plant for the European XFEL

    Science.gov (United States)

    Blum, L.; Wilhelm, H.; Petersen, B.; Schnautz, T.

    2015-12-01

    The European XFEL project is under construction at DESY in Germany. The superconducting XFEL linac is supplied by the XFEL helium refrigerator plant. This plant consists of two existing refrigerators, which were in service for the HERA storage ring until 2007. Since the XFEL linear accelerator requires cryogenic cooling at 2K, the existing cryogenic infrastructure had to be modified. Two of the three existing HERA helium refrigerators were required to cover the design heat load of the XFEL-linac. The refrigerator infrastructure was extended by a 2 K cooling loop, whose main component consists of a string of four cold compressors generating approximately 1.7 kW isothermal cooling capacity at 2K. The step by step commissioning and extension of the accelerator as well as the future upgrade option of the heat load demanded an extremely high turn down ability, a particular challenge for 2K cold compressor strings. The commissioning of the helium refrigerator infrastructure is underway and should be completed soon. The current status of this project, commissioning results and particular challenges are presented.

  13. Concept of quasi-periodic undulator - control of radiation spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Shigemi [Japan Atomic Energy Research Institute, Ibaraki (Japan)

    1995-02-01

    A new type of undulator, the quasi-periodic undulator (QPU) is considered which generates the irrational harmonics in the radiation spectrum. This undulator consists of the arrays of magnet blocks aligned in a quasi-periodic order, and consequentially lead to a quasi-periodic motion of electron. A combination of the QPU and a conventional crystal/grating monochromator provides pure monochromatic photon beam for synchrotron radiation users because the irrational harmonics do not be diffracted in the same direction by a monochromator. The radiation power and width of each radiation peak emitted from this undulator are expected to be comparable with those of the conventional periodic undulator.

  14. Generation of radiation by intense plasma and electromagnetic undulators

    International Nuclear Information System (INIS)

    We examine the characteristics of the classical radiation emission resulting from the interaction of a relativistic electron beam that propagates perpendicularly through a large amplitude relativistic plasma wave. Such a study is useful for evaluating the feasibility of using relativistic plasma waves as extremely short wavelength undulators for generating short wavelength radiation. The electron trajectories in a plasma wave undulator and in an ac FEL undulator are obtained using perturbation techniques. The spontaneous radiation frequency spectrum and angular distribution emitted by a single electron oscillating in these two undulators are then calculated. The radiation gain of a copropagating electromagnetic wave is calculated. The approximate analytic results for the trajectories, spontaneous radiation and gain are compared with 3-D simulation results. The characteristics of the plasma wave undulator are compared with the ac FEL undulator and linearly polarized magnetic undulator. 50 refs., 26 figs., 3 tabs

  15. Estimation of emittance degradation due to multi-pole fields of XFEL bunch compressors

    International Nuclear Information System (INIS)

    In order to obtain a high-brightness electron beam in an XFEL, the electron bunch should be longitudinally compressed in a linear accelerator using magnetic bunch compressors composed of four bending magnets. The bunch compression requires a large energy chirp on the electron bunch, which produces a horizontal spread of the beam size inside bunch compressors. Since the bending magnets have multi-pole field components, they leak energy-dispersion and degrade emittance downstream of the chicane. In this paper, the emittance degradation due to the multi-pole fields of the bending magnets is estimated using simplified analytical formulae for the XFEL/SPring-8. (author)

  16. Front end ASIC for AGIPD, a high dynamic range fast detector for the European XFEL

    International Nuclear Information System (INIS)

    The Adaptive Gain Integrating Pixel Detector (AGIPD) is a hybrid pixel X-ray detector for the European-XFEL. One of the detector's important parts is the radiation tolerant front end ASIC fulfilling the European-XFEL requirements: high dynamic range—from sensitivity to single 12.5keV-photons up to 104 photons. It is implemented using the dynamic gain switching technique with three possible gains of the charge sensitive preamplifier. Each pixel can store up to 352 images in memory operated in random-access mode at ≥4.5 MHz frame rate. An external vetoing may be applied to overwrite unwanted frames

  17. Perspectives of Imaging of Single Protein Molecules with the Present Design of the European XFEL. - Part I - X-ray Source, Beamlime Optics and Instrument Simulations

    CERN Document Server

    Serkez, Svitozar; Saldin, Evgeni; Zagorodnov, Igor; Geloni, Gianluca; Yefanov, Oleksandr

    2014-01-01

    The Single Particles, Clusters and Biomolecules (SPB) instrument at the European XFEL is located behind the SASE1 undulator, and aims to support imaging and structure determination of biological specimen between about 0.1 micrometer and 1 micrometer size. The instrument is designed to work at photon energies from 3 keV up to 16 keV. This wide operation range is a cause for challenges to the focusing optics. In particular, a long propagation distance of about 900 m between x-ray source and sample leads to a large lateral photon beam size at the optics. The beam divergence is the most important parameter for the optical system, and is largest for the lowest photon energies and for the shortest pulse duration (corresponding to the lowest charge). Due to the large divergence of nominal X-ray pulses with duration shorter than 10 fs, one suffers diffraction from mirror aperture, leading to a 100-fold decrease in fluence at photon energies around 4 keV, which are ideal for imaging of single biomolecules. The nominal...

  18. Exact relativistic theory of geoid's undulation

    CERN Document Server

    Kopeikin, Sergei; Karpik, Alexander

    2014-01-01

    Precise determination of geoid is one of the most important problem of physical geodesy. The present paper extends the Newtonian concept of the geoid to the realm of Einstein's general relativity and derives an exact relativistic equation for the unperturbed geoid and level surfaces under assumption of axisymmetric distribution of background matter in the core and mantle of the Earth. We consider Earth's crust as a small disturbance imposed on the background distribution of matter, and formulate the master equation for the anomalous gravity potential caused by this disturbance. We find out the gauge condition that drastically simplifies the master equation for the anomalous gravitational potential and reduces it to the form closely resembling the one in the Newtonian theory. The master equation gives access to the precise calculation of geoid's undulation with the full account for relativistic effects not limited to the post-Newtonian approximation. The geoid undulation theory, given in the present paper, uti...

  19. Conceptual design of a plasma undulator

    Science.gov (United States)

    Suzuki, Yasuo

    1993-07-01

    A micropitched plasma undulator is proposed for the first time. It is composed of an array of hundreds of discharged and pinched slender columns of plasma. Two kinds of undulating forces on the electron beam can be considered: one is a periodic magnetic field generated by the electric currents flowing through the array of the small radius plasma columns and the other is a periodic electrostatic field generated by the interaction of the relativistic electron beam with the rippled density of the plasma. Methods for both producing and stabilizing the array of the plasma columns are discussed. The effects of collisions between the plasma particles and the electron beam on the orbit and the momentum of the electrons are also discussed, leading to the conclusion that they can be negligibly small, as far as the gas pressure in the chamber leaking from the plasma region does not disturb the performance of the electron accelerator.

  20. Thermal analysis of superconducting undulator cryomodules

    Science.gov (United States)

    Shiroyanagi, Y.; Doose, C.; Fuerst, J.; Harkay, K.; Hasse, Q.; Ivanyushenkov, Y.; Kasa, M.

    2015-12-01

    A cryocooler-cooled superconducting undulator (SCU0) has been operating in the Advanced Photon Source (APS) storage ring since January of 2013. Based on lessons learned from the construction and operation of SCU0, a second superconducting undulator (SCU1) has been built and cold tested stand-alone. An excess cooling capacity measurement and static heat load analysis show a large improvement of cryogenic performance of SCU1 compared with SCU0. ANSYS-based thermal analysis of these cryomodules incorporating all the cooling circuits was completed. Comparisons between measured and calculated temperatures at the three operating conditions of the cryomodule (static, beam heat only, beam heat and magnet current) will be presented.

  1. In vacuum undulator task force report

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, J.B.; Kao, C.C.; Stefan, P. [and others

    1998-06-01

    Historically the NSLS has been active in R&D for state-of-the-art electron beams, photon beams and x-ray optics. One of the available straight sections has therefore been dedicated to insertion device R&D. Over the past five to seven years a program aimed at exploiting the very small vertical {beta} function in the straight sections has yielded first a prototype small gap undulator (PSGU) and then an in-vacuum undulator (IVUN). The IVUN sources attain a brightness similar to the existing hybrid wigglers in X21 and X25. They radiate significantly lower total power than the wigglers but produce higher power densities. They provide undulator rather than wiggler spectra. Because of the small gaps and small periods there is not much tunability in these devices and they will have to be purpose-built for a specific scientific program. The original IVUN parameters were chosen for in-elastic x-ray scattering, similar to the scientific program on X21. This put the fundamental at 4.6 keV and the third harmonic at 13.8 keV. The question that this new possible insertion device poses is what science programs can best take advantage of this new insertion device source? To answer this, a task force was formed by M. Hart, NSLS Department Chair and charged with identifying viable scientific programs that could seek outside funding to construct IVUN beamlines. The task force concentrated on experimental programs that are presently being pursued on new insertion devices worldwide. For example, x-ray photon correlation spectroscopy, which takes advantage of the large coherent flux from undulator sources, was considered. However, this program was not considered as the highest priority. The general area of protein crystallography, however, is ideal for the IVUN source. The unique electron beam optics that makes the IVUN possible in the first place also makes the IVUN ideal as a source for microdiffraction.

  2. Feasibility of Diagnostics Undulator Studies at ASTA

    OpenAIRE

    Lumpkin, A. H.; Wendt, M.; Byrd, J. M.

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) facility is currently under construction at Fermilab. With a 1-ms macropulse composed of up to 3000 micropulses and with beam energies projected from 45 to 800 MeV, the need for non-intercepting diagnostics for beam size, position, energy, and bunch length is clear. In addition to the rf BPMs, optical synchrotron radiation (OSR), and optical diffraction radiation (ODR) techniques already planned, we propose the use of undulator radiation fr...

  3. Undulator-based production of polarized positrons

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, G. [Tel-Aviv Univ. (Israel); Barley, J. [Cornell Univ., Ithaca, NY (United States); Batygin, Y. [SLAC, Menlo Park, CA (US)] (and others)

    2009-05-15

    Full exploitation of the physics potential of a future International Linear Collider will require the use of polarized electron and positron beams. Experiment E166 at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme in which an electron beam passes through a helical undulator to generate photons (whose first-harmonic spectrum extended to 7.9 MeV) with circular polarization, which are then converted in a thin target to generate longitudinally polarized positrons and electrons. The experiment was carried out with a one-meter-long, 400-period, pulsed helical undulator in the Final Focus Test Beam (FFTB) operated at 46.6 GeV. Measurements of the positron polarization have been performed at five positron energies from 4.5 to 7.5 MeV. In addition, the electron polarization has been determined at 6.7MeV, and the effect of operating the undulator with a ferrofluid was also investigated. To compare the measurements with expectations, detailed simulations were made with an upgraded version of GEANT4 that includes the dominant polarization-dependent interactions of electrons, positrons, and photons with matter. The measurements agree with calculations, corresponding to 80% polarization for positrons near 6 MeV and 90% for electrons near 7 MeV. (orig.)

  4. Undulator-Based Production of Polarized Positrons

    CERN Document Server

    Alexander, Gideon; Batygin, Yuri; Berridge, Steven; Bharadwaj, Vinod; Bower, Gary; Bugg, William; Decker, Franz-Josef; Dollan, Ralph; Efremenko, Yuri; Floettmann, Klaus; Gharibyan, Vahagn; Hast, Carsten; Iverson, Richard; Kolanoski, Hermann; Kovermann, Jan W; Laihem, Karim; Lohse, Thomas; McDonald, Kirk T; Mikhailichenko, Alexander A; Moortgat-Pick, Gudrid; Pahl, Philipp; Pitthan, Rainer; Poeschl, Roman; Reinherz-Aronis, Erez; Riemann, Sabine; Schaelicke, Andreas; Schueler, Klaus-Peter; Schweizer, Thomas; Scott, Duncan; Sheppard, John C; Stahl, Achim; Szalata, Zenon; Walz, Dieter R; Weidemann, Achim

    2009-01-01

    Full exploitation of the physics potential of a future International Linear Collider will require the use of polarized electron and positron beams. Experiment E166 at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme in which an electron beam passes through a helical undulator to generate photons (whose first-harmonic spectrum extended to 7.9MeV) with circular polarization, which are then converted in a thin target to generate longitudinally polarized positrons and electrons. The experiment was carried out with a one-meter-long, 400-period, pulsed helical undulator in the Final Focus Test Beam (FFTB) operated at 46.6GeV. Measurements of the positron polarization have been performed at five positron energies from 4.5 to 7.5MeV. In addition, the electron polarization has been determined at 6.7MeV, and the effect of operating the undulator with a ferrofluid was also investigated. To compare the measurements with expectations, detailed simulations were made with an upgraded version of Geant4...

  5. Undulator-based production of polarized positrons

    International Nuclear Information System (INIS)

    Full exploitation of the physics potential of a future International Linear Collider will require the use of polarized electron and positron beams. Experiment E166 at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme in which an electron beam passes through a helical undulator to generate photons (whose first-harmonic spectrum extended to 7.9 MeV) with circular polarization, which are then converted in a thin target to generate longitudinally polarized positrons and electrons. The experiment was carried out with a one-meter-long, 400-period, pulsed helical undulator in the Final Focus Test Beam (FFTB) operated at 46.6 GeV. Measurements of the positron polarization have been performed at five positron energies from 4.5 to 7.5 MeV. In addition, the electron polarization has been determined at 6.7MeV, and the effect of operating the undulator with a ferrofluid was also investigated. To compare the measurements with expectations, detailed simulations were made with an upgraded version of GEANT4 that includes the dominant polarization-dependent interactions of electrons, positrons, and photons with matter. The measurements agree with calculations, corresponding to 80% polarization for positrons near 6 MeV and 90% for electrons near 7 MeV. (orig.)

  6. Operation of the ANKA Synchrotron Light Source with Superconductive Undulators

    CERN Document Server

    Rossmanith, Robert; Bernhard, Axel; Hagelstein, Michael; Kostka, Barbara; Steffens, Erhard; Weisser, Matthias; Wollmann, D

    2005-01-01

    The synchrotron light source ANKA (2.5 GeV, 200 mA) is a versatile multi-purpose storage ring with beam lines for coherent IR and THz radiation (IR-laser), LIGA applications and high brilliance X-rays. It is now plannned to install in addition several superconductive undulators for a wide range of applications: fast tunable X-rays for material research, imaging applications and an undulator with variable polarization direction for a dichroism beamline. This development of ANKA is the result of successful research on superconductive undulators which surpass the performance of permanent undulators by far (collaboration between ANKA, the University of Karlsruhe and the University of Erlangen-Nürnberg). The basic layout of the undulators and the required changes to a storage ring to accommodate the superconductive undulators is described in this paper.

  7. Highlights from e-EPS: New milestone reached for the European XFEL construction

    CERN Multimedia

    Jorge Rivero González

    2013-01-01

    e-EPS News is an addition to the CERN Bulletin line-up, showcasing articles from e-EPS – the European Physical Society newsletter – as part of a collaboration between the two publications.   In June 2013 an important milestone was reached for the European X-ray free-electron laser [XFEL] with the completion of its underground portion. Located in the Hamburg area (Germany), the European XFEL is one of the largest and most ambitious European projects to date. Starting full operations in 2016, the European XFEL is expected to generate intensive, ultrashort X-ray flashes that will open up entirely new areas of research with X-rays that are currently inaccessible. Organisations from 12 European countries, Denmark, France, Germany, Greece, Hungary, Italy, Poland, Russia, Slovakia, Spain, Sweden and Switzerland are members of the European XFEL consortium, with the Deutsches Elektronen-Synchrotron [DESY] as the main shareholder. The total length of the facility will be 3.4km and ...

  8. Optics Compensation for Variable-gap Undulator Systems at FLASH

    OpenAIRE

    Amstutz, Philipp; Lechner, Christoph; Plath, Tim; Ackermann, Sven; Boedewadt, Joern; Vogt, Mathias

    2015-01-01

    Variable-gap undulator systems are widely used in storage rings and linear accelerators to generate soft- and hard x-ray radiation for the photon science community. For cases where the effect of undulator focusing significantly changes the electron beam optics, a compensation is needed in order to keep the optics constant in other parts of the accelerator. Since 2010, the free-electron laser (FEL) facility FLASH is equipped with two undulator sections along the same electron beamline. The fir...

  9. Undulator radiation carrying spin and orbital angular momentum

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Shigemi [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)], E-mail: sasaki@aps.anl.gov; McNulty, Ian; Dejus, Roger [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2007-11-11

    We show that the radiation from a helical undulator not only carries spin angular momentum (circular polarization) but also orbital angular momentum. This exotic property of the undulator radiation may be useful in coherent X-ray imaging and scattering experiments and to probe electronic transitions in matter by orbital dichroism spectroscopy. Also, we present that a new magnet configuration, similar to the structure of Figure-8 undulator or the PERA undulator, may generate right- and left-hand circularly polarized off-axis radiation simultaneously.

  10. Undulator radiation carrying spin and orbital angular momentum.

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, S.; McNulty, I.; Dejus, R.; X-Ray Science Division

    2007-11-11

    We show that the radiation from a helical undulator not only carries spin angular momentum (circular polarization) but also orbital angular momentum. This exotic property of the undulator radiation may be useful in coherent X-ray imaging and scattering experiments and to probe electronic transitions in matter by orbital dichroism spectroscopy. Also, we present that a new magnet configuration, similar to the structure of Figure-8 undulator or the PERA undulator, may generate right- and left-hand circularly polarized off-axis radiation simultaneously.

  11. Research on Complexity of Surface Undulating Shapes of Rock Joints

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The surface undulating shapes of rock joints have been described qualitatively or experimental-quantitatively for a long time. The non-determined describing method can not fit quantitative evaluation of mechanical parameters of rock joints in engineering. In this paper, relative amplitude (RA) is chosen as a quantitative-describing index of surface measurement of 1 023 surface undulating curves which conducted by profile curve device(PCD). We discuss the nonuniformity,anisotropy and unhomogeneity of surface undulating shapes of joints. A new method that analyzes the complexity of surface undulating shapes of rock joints directional-statistically in various rock joints is also put forward.

  12. Analysis of misalignment effects on optical Klystron undulator radiation

    International Nuclear Information System (INIS)

    In an optical klystron undulator, a long drift space or a shorter dispersive magnet is placed in between the two undulator sections. The resonance interaction between the electron and the electromagnetic wave is turned off in the drift/dispersive magnet section which leads to a change of the electron phase. The electrons under go bunching and density modulation in response to the change of electron phase and the radiation is enhanced. A requirement of the dispersive magnet field is that both the first and second field integral in the length of the dispersive section must be zero to ensure zero net transverse and zero angular displacement of the electron at the input of the second undulator section of the optical klystron. Similar condition too holds good for the long drift space case where the electron is made to enter the second undulator without any change in its angular or transverse displacement. In this paper, we remove these constraints to analyze the important effects of optical klystron undulator radiation with an angular and axial offset of the relativistic electron beam in the second undulator section through an analytic approach. An analytical expression for the undulator radiation is obtained through a simple and transparent procedure. It is shown that the misalignment effects are more severe for longer undulator lengths and with higher dispersive field strengths. Both these effects are less pronounced for undulators with large K values. (author)

  13. Layout considerations on the 25GeV/300kW beam dump of the XFEL project

    International Nuclear Information System (INIS)

    The European X-Ray Free Electron Laser (XFEL) project, which is currently under design at DESY, requires 3 beam dumps downstream of the accelerator. By means of energy deposition, temperature and mechanical stress calculations the layout of a solid edge cooled beam dump is presented. This dump is able to withstand a high cyclic impact, as induced by each subsequent bunch train of up to 2.5.1013 electrons in combination with a large amount of dissipated power density (∼1.8 kW/cm) coming from a beam with an average power of up to 300 kW at a variable energy up to 25 GeV. The cyclic impact is faced by using graphite as a core material in the dump and setting a lower limit for the incoming beam size at σbeam≥2 mm. Introducing a slow (not within the bunch train) circular beam sweep answers the question of heat extraction. Alternative layouts are investigated in order to avoid active beam sweeping. Unfortunately more severe risks and disadvantages are coming along with them. That is why theses solutions are not regarded as reliable alternatives and the dump design with beam sweeping is considered to be the baseline solution, for which a technical layout is under way. (orig.)

  14. Undulations from amplified low frequency surface waves

    International Nuclear Information System (INIS)

    We study the linear scattering of gravity waves in longitudinal inhomogeneous stationary flows. When the flow becomes supercritical, it is known that counterflow propagating shallow waves are blocked and converted into deep waves. Here we show that in the zero-frequency limit, the reflected waves are amplified in such a way that the free surface develops an undulation, i.e., a zero-frequency wave of large amplitude with nodes located at specific places. This amplification involves negative energy waves and implies that flat surfaces are unstable against incoming perturbations of arbitrary small amplitude. The relation between this instability and black hole radiation (the Hawking effect) is established

  15. Undulations from amplified low frequency surface waves

    CERN Document Server

    Coutant, Antonin

    2012-01-01

    We study the scattering of gravity waves in longitudinal stationary flows. When the flow velocity becomes supercritical, counterflow propagating waves are amplified in such a way that, in the zero-frequency limit, the free surface develops an undu- lation, i.e., a zero-frequency wave of large amplitude with nodes located at specific places. From this, we show that the unperturbed flat surface is unstable against perturbations of arbitrary small amplitude. We then show that this instability also appears when treating low frequency waves by a stochastic ensemble. The relation between the generation of undulations and black hole radiation (the Hawking effect) is discussed.

  16. Undulating periodization models for strength training & conditioning

    Directory of Open Access Journals (Sweden)

    A. Jiménez

    2009-01-01

    Full Text Available Periodized strength training refers to varying the training program at regular time intervals in an attempt to bring about optimal resistance gains. The main aim of this paper was to present a short review of the diferent aspects of training periodization and its effects with performance. as well as the differential effect of alternate periodization models on other populations, and specially the need for further research regarding the effectiveness of the undulating model as compared with the linear model. A focussed literature review reveals that most studies that examined strength training periodization utilized young males as their subject population, and the research has mainly focused on differences between periodized and non-periodized programs. Furthermore, the periodization training programs are designed and developed according to two different models: the linear model and the non-linear model. The Linear Model is characterized by high initial training volume and low and intensity. The Non-Linear Model enables variation in intensity and volume within each 7-10 day cycle by rotating different protocols to train various components of the neuromuscular system. The results showed at the scientific literature encourage researchers and exercise professionals to include non-linear (undulating periodization models during resistance training.

  17. Resistive Wall Wakefield in the LCLS Undulator

    CERN Document Server

    Bane, Karl Leopold Freitag

    2005-01-01

    In the Linac Coherent Light Source (LCLS), a short, intense bunch (rms length 20 microns, bunch charge 1 nC) will pass through a small, long undulator beam pipe (radius 2.5 mm, length 130 m). The wakefields in the undulator, particularly the resistive wall wake of the beam pipe, will induce an energy variation along the bunch, a variation that needs to be kept to within a few times the Pierce parameter for all beam particles to continue to lase. Earlier calculations included the short-range resistive wall wake, but did not include the frequency dependence of conductivity (ac conductivity) of the beam pipe walls. We show that for copper and for the LCLS bunch structure, including the ac conductivity results in a very large effect. We show that the effect can be ameliorated by choosing aluminum and also by taking a flat, rather than round, beam pipe chamber (if the vertical aperture is fixed). The effect of the (high frequency) anomalous skin effect is also considered.

  18. The adjustable phase planar helical undulator

    International Nuclear Information System (INIS)

    The study of magnetic and biological materials which exhibit magnetic circular dichroism has created a demand for circularly polarized x-rays whose helicity may be switched between the right and left hand senses. At present, circularly polarized x-rays are obtained from storage ring bending magnets by accepting radiation from above and below the axis, but insertion device sources are desired for greater intensity. Planar helical undulators are magnetic insertion devices that generate helical magnetic fields. The charged particle beam executes a helical trajectory in the device, and produces elliptically polarized x-rays. The special case of circularly polarized x-rays is most in demand. We present here the design description of a new type of planar helical undulator, which we are constructing for the SPEAR storage ring at the Stanford Synchrotron Radiation Laboratory (SSRL). It comprises four rows of pure permanent magnet blocks, one row in each quadrant about the axis defined by the electron beam. Rows may be translated longitudinally with respect to each other to change the helicity of the magnetic field they create at the position of the beam. They may also be translated longitudinally to vary the energy of the x-rays emitted, unlike designs where this function is performed by varying the gap between the rows. This work includes numerical calculations of the fields, electron trajectories, x-ray spectra, off-axis effects, and mechanical design considerations

  19. Cosmological constraints on the Undulant Universe

    Institute of Scientific and Technical Information of China (English)

    Tian Lan; Yan Gong; Hao-Yi Wan; Tong-Jie Zhang

    2010-01-01

    We use the redshifi Hubble parameter H(z)data derived from relative galaxy ages,distant type Ⅰa supernovae(SNe Ⅰa),the Baryonic Acoustic Oscillation (BAO)peak,and the Cosmic Microwave Background(CMB)shift parameter data,to constrain cosmological parameters in the Undulant Universe.We marginalize the likelihood functions over h by integrating the probability density P ∝ e-x2/2.By using a Markov Chain Monte Carlo(MCMC)technique,we obtain the best fitting results and give the confidence regions in the b-Ωm0 plane.Then we compare their constraints.Our results show that the H(z)data play a similar role with the SNe Ia data in cosmological study.By presenting the independent and joint constraints,we find that the BAO and CMB data play very important roles in breaking the degeneracy compared with the H(z)and SNe Ⅰa data alone.Combined with the BAO or CMB data,one can remarkably improve the constraints.The SNe Ia data sets constrain Ωm0 much tighter than the H(z)data sets,but the H(z)data sets constrain b much tighter than the SNe Ⅰa data sets.All these results show that the Undulant Universe approaches the ACDM model.We expect more H(z)data to constrain cosmological parameters in the future.

  20. Cosmological constraints on the Undulant Universe

    International Nuclear Information System (INIS)

    We use the redshift Hubble parameter H(z) data derived from relative galaxy ages, distant type Ia supernovae (SNe Ia), the Baryonic Acoustic Oscillation (BAO) peak, and the Cosmic Microwave Background (CMB) shift parameter data, to constrain cosmological parameters in the Undulant Universe. We marginalize the likelihood functions over h by integrating the probability density P ∝ e-χ2/2 By using a Markov Chain Monte Carlo (MCMC) technique, we obtain the best fitting results and give the confidence regions in the b - Ωm0 plane. Then we compare their constraints. Our results show that the H(z) data play a similar role with the SNe Ia data in cosmological study. By presenting the independent and joint constraints, we find that the BAO and CMB data play very important roles in breaking the degeneracy compared with the H(z) and SNe Ia data alone. Combined with the BAO or CMB data, one can remarkably improve the constraints. The SNe Ia data sets constrain Ωm0 much tighter than the H(z) data sets, but the H(z) data sets constrain b much tighter than the SNe Ia data sets. All these results show that the Undulant Universe approaches the ΛCDM model. We expect more H(z) data to constrain cosmological parameters in the future. (research papers)

  1. Design of the mirror optical systems for coherent diffractive imaging at the SPB/SFX instrument of the European XFEL

    Science.gov (United States)

    Bean, Richard J.; Aquila, Andrew; Samoylova, Liubov; Mancuso, Adrian P.

    2016-07-01

    The high degree of spatial coherence and extreme pulse energies available at x-ray free electron laser (XFEL) sources naturally support coherent diffractive imaging applications. In order to optimally exploit these unique properties, the optical systems at XFELs must be highly transmissive, focus to appropriate sizes matched to the scale of samples to be investigated and must minimally perturb the wavefront of the XFEL beam. We present the design and simulated performance of two state-of-the-art Kirkpatrik–Baez mirror systems that form the primary foci of the single particles, clusters and biomolecules and serial femtosecond crystallography (SPB/SFX) instrument of the European XFEL. The two systems, presently under construction, will produce 1 μm and 100 nm scale foci across a 3–16 keV photon energy range. Targeted applications include coherent imaging of weakly scattering, often biological, specimens.

  2. Short-Period RF Undulator for a SASE Nanometer source

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2001-12-21

    Analysis is described towards development of a RF undulator with a period < 1 cm, an undulator parameter K of the order of unity, and a gap greater than 2.25 mm. The application for the undulator is for a SASE source to produce 1 nm wavelength radiation using a low energy electron beam in the range 1-2 GeV. Particle orbit calculations in a conventional standing-wave resonator configuration show that the presence of a co-propagating component of RF field can cause deleterious motion for the undulating electrons that can seriously degrade their radiation spectrum. To obviate this problem, resonator designs were devised in which only the counter-propagating field components interact with the particles. Two resonator configurations with the same undulator parameter K = 0.4 have been devised and are described in this report.

  3. Auroral Undulations During Magnetic Storms: TIMED/GUVI Observations

    Science.gov (United States)

    Zhang, Y.; Paxton, L. J.; Morrison, D.; Lui, T.; Kil, H.; Wolven, B.; Meng, C. I.

    2005-05-01

    Giant undulations on the equatorward edge of the diffuse aurora have been identified in TIMED/GUVI auroral images in the far ultraviolet wavelengths. Some new features have been observed: (1) The GUVI 121.6nm auroral images provide direct optical evidence that the undulations occur in the proton aurora, (2) Undulations are not limited to the dusk sector, they can occur in all local time sectors, (3) Both large ionospheric ion drift velocity (1000 m/s and above) and strong velocity shear (> 0.1 1/s) appear to be a necessary condition for the undulation to occur, (4) While almost all of the undulation events are observed during magnetic storms (Dst K-H instability.

  4. On the Single-Photon-Counting (SPC) modes of imaging using an XFEL source

    International Nuclear Information System (INIS)

    The requirements to achieve high detection efficiency (above 50%) and gigahertz (GHz) frame rate for the proposed 42-keV X-ray free-electron laser (XFEL) at Los Alamos are summarized. Direct detection scenarios using C (diamond), Si, Ge and GaAs semiconductor sensors are analyzed. Single-photon counting (SPC) mode and weak SPC mode using Si can potentially meet the efficiency and frame rate requirements and be useful to both photoelectric absorption and Compton physics as the photon energy increases. Multilayer three-dimensional (3D) detector architecture, as a possible means to realize SPC modes, is compared with the widely used two-dimensional (2D) hybrid planar electrode structure and 3D deeply entrenched electrode architecture. Demonstration of thin film cameras less than 100-μm thick with onboard thin ASICs could be an initial step to realize multilayer 3D detectors and SPC modes for XFELs

  5. On the Single-Photon-Counting (SPC) modes of imaging using an XFEL source

    CERN Document Server

    Wang, Zhehui

    2015-01-01

    The requirements to achieve high detection efficiency (above 50\\%) and gigahertz (GHz) frame rate for the proposed 42-keV X-ray free-electron laser (XFEL) at Los Alamos are summarized. Direct detection scenarios using C (diamond), Si, Ge and GaAs semiconductor sensors are analyzed. Single-photon counting (SPC) mode and weak SPC mode using Si can potentially meet the efficiency and frame rate requirements and be useful to both photoelectric absorption and Compton physics as the photon energy increases. Multilayer three-dimensional (3D) detector architecture, as a possible means to realize SPC modes, is compared with the widely used two-dimensional (2D) hybrid planar electrode structure and 3D deeply entrenched electrode architecture. Demonstration of thin film cameras less than 100-$\\mu$m thick with onboard thin ASICs could be an initial step to realize multilayer 3D detectors and SPC modes for XFELs.

  6. Absorbed XFEL Dose in the Components of the LCLS X-Ray Optics

    Energy Technology Data Exchange (ETDEWEB)

    Hau-Riege, Stefan

    2010-12-03

    There is great concern that the short, intense XFEL pulse of the LCLS will damage the optics that will be placed into the beam. We have analyzed the extent of the problem by considering the anticipated materials and position of the optical components in the beam path, calculated the absorbed dose as a function of photon energy, and compared these doses with the expected doses required (i) to observe rapid degradation due to thermal fatigue, (ii) to reach the melting temperature, or (iii) to actually melt the material. We list the materials that are anticipated to be placed into the Linac Coherent Light Source (LCLS) x-ray free electron laser (XFEL) beam line, their positions, and the absorbed dose, and compare this dose with anticipated damage thresholds.

  7. Testing of the First Part of Series Production 10MW MBKs for the XFEL Project

    OpenAIRE

    Vogel, Vladimir; Butkowski, Lukasz; Choroba, Stefan; Cherepenko, Andrey; Hartung, Jens; Kachaev, Vladimir; Wagner, Richard

    2014-01-01

    At present more than half of 27 of 10 MW horizontal multi-beam klystrons (MBK) manufactured by two companies for the European XFEL project have been delivered to DESY. After delivery each klystron is connected to the connection module (CM), a HV oil tank with integrated HV connector, voltage and current monitors and a coaxial filament transformer, tested on the test stand and, if necessary conditioned. After this the klystrons are ready for installation in the underground linear accelerator t...

  8. Resource Letter on Stimulated Inelastic X-ray Scattering at an XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Bruce D.; /SLAC

    2010-09-02

    At sufficient X-ray intensity, stimulated effects in inelastic scattering will become important. These coherent, non-linear optical phenomena may be used to impulsively produce a high degree of collective excitation in, for example, correlated electron materials, suitable for performing ultrafast time-resolved spectroscopy. This Resource Letter collects information on fundamental aspects of stimulated X-ray scattering and evaluates the prospect for successful experiments at a present or future X-ray free electron laser (XFEL) facility.

  9. Development of the DAQ Front-end for the DSSC Detector at the European XFEL

    OpenAIRE

    Gerlach, Thomas

    2013-01-01

    The European XFEL is an international photon science facility currently under construction at DESY, Hamburg. Its unique characteristics will open up new research opportunities for investigating tiny structures, ultra-fast processes, and also matter under extreme conditions. The research will allow invaluable insights for many scientific disciplines like biology, medicine, and chemistry, but also for nano-technology, astro-physics, and others. The DSSC detector is one of thre...

  10. Optical video disks with undulating tracks.

    Science.gov (United States)

    Braat, J J; Bouwhuis, G

    1978-07-01

    The signal components of a video signal (luminance, color, and sound) are modulated on a main carrier and several subcarriers and then recorded on the video master disk. Apart from the signal distortion that can arise during master and disk manufacture, the optical readout of the disk also yields a nonlinear transfer of the signal. The result of nonlinearities is intermodulation between signal components. Intermodulation products affect the quality of the final TV picture. In this paper a method is described which reduces the contribution of the optical readout system to the intermodulation. An optical coding is introduced such that two signal components hardly influence one another. The spacing of the pits in the track direction carries the luminance information, while the undulation of the track carries the color or sound information. A quadrant photodetector positioned in the far field of the video disk restores the luminance and color or sound bands with a very low amount of intermodulation. PMID:20203718

  11. Feasibility of Diagnostics Undulator Studies at ASTA

    CERN Document Server

    Lumpkin, A H; Byrd, J M

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) facility is currently under construction at Fermilab. With a 1-ms macropulse composed of up to 3000 micropulses and with beam energies projected from 45 to 800 MeV, the need for non-intercepting diagnostics for beam size, position, energy, and bunch length is clear. In addition to the rf BPMs, optical synchrotron radiation (OSR), and optical diffraction radiation (ODR) techniques already planned, we propose the use of undulator radiation from a dedicated device for diagnostics. with a nominal period of 4-5 cm, a tunable field parameter K, and a length of several meters. The feasibility of extending such techniques in the visible regime at a beam energy of 125 MeV into the UV and VUV regimes with beam energies of 250 and 500 MeV will be presented.

  12. Study of X-ray radiation damage in the AGIPD sensor for the European XFEL

    CERN Document Server

    Zhang, Jiaguo; Graafsma, Heinz; Klanner, Robert; Kopsalis, Ioannis; Schwandt, Joern

    2013-01-01

    The European X-ray Free Electron Laser (XFEL), currently being constructed in Hamburg and planning to be operational in 2017 for users, will deliver 27,000 fully coherent, high brilliance X-ray pulses per second with duration less than 100 fs. The unique features of the X-ray beam pose major challenges for detectors used at the European XFEL for imaging experiments, in particular a radiation tolerance of silicon sensors for doses up to 1 GGy for 3 years of operation at an operating voltage above 500 V. One of the detectors under development at the European XFEL is the Adaptive Gain Integrating Pixel Detector (AGIPD), which is a hybrid detector system with ASICs bump-bonded to p+n silicon pixel sensors. We have designed the silicon sensors for the AGIPD, which have been fabricated by SINTEF and delivered in the beginning of February of 2013. To demonstrate the performance of the AGIPD sensor with regard to radiation hardness, mini-sensors with the same pixel and guard-ring designs as the AGIPD together with te...

  13. Magnetic design for Knot-APPLE undulator and its performance

    International Nuclear Information System (INIS)

    In order to generate a low energy photon beam in a high energy storage ring with an insertion device, it is necessary to increase the undulator's deflection parameter, K. If this is the case, a high heat load on beamline elements is a serious problem because the on-axis radiation power increases drastically as increasing K parameter for a linear undulator. To overcome this problem, a Figure-8, a Pera, a Knot undulator were proposed. However, these undulators cannot change polarizations. On the other hand, APPLE undulator is capable for generating variable polarization. A novel Knot-APPLE undulator was proposed. It is capable for reducing on-axis high heat load and generating every polarization state. But we have some difficulties for displacing radiation power peak from higher harmonics off-axis due to differences in gap dependence between horizontal field and vertical one especially in vertical linear mode for a present magnet structure. In this paper, we looked for most appropriate magnet size and structure to obtain ideal magnetic field in every polarization state. In the presentation, we show radiation spectra and corresponding power density distributions expected from another possible magnet structure for Knot-APPLE undulator. (author)

  14. Study of undulator magnetic field measurement using vibrating wire method

    International Nuclear Information System (INIS)

    A test accelerator for a terahertz source project (t-ACTS) has been progressed at the Electron Light Science Centre, Tohoku University, in which a generation of intense coherent terahertz radiation from the very short electron bunch will be demonstrated. A narrow-band coherent terahertz radiation using an undulator has been considered to be implemented. We have constructed a planer undulator that is basically a Halbach type composed of permanent magnet blocks. The period length of the undulator and the number of periods are 100 mm and 25, respectively. The vibrating wire method is studied to measure the periodic magnetic field of the undulator. A thin copper-beryllium wire is placed on beam axis in the undulator, and an AC current flow is applied in the wire. By measuring amplitudes and phases of standing waves excited on the wire by the Lorentz force between AC current and magnetic field, we can reconstruct the magnetic field distribution along the wire. We discuss relations between reproducibility of the undulator field and the mode harmonics number used for the reconstruction of undulator field. (author)

  15. Spontaneous emission spectra from a staggered-array undulator

    International Nuclear Information System (INIS)

    A staggered-array undulator set inside the superconducting solenoid coils is shown to be able to provide high undulator fields larger than the longitudinal magnetic fields, a small undulator period, easy tunability through the solenoid coil current, and compact and easy fabrication. The overall performance characteristics of this undulator were studied mainly with respect to iron and aluminum disk widths, and spontaneous emission spectra through the numerical calculations. The maximum undulator field is found to be obtained for the ratio of the aluminum disk width to the undulator period of 0.45. The line widths (FWHM) of the spontaneous emission spectra, however, do not show Nw-1 dependence on the number of the undulator period Nw for practical beams with a Gaussian distribution, compared with for a single electron. The energy spread among various parameters is seen to play an important role in reducing the FWHM with increase of Nw. The large tunability of the wavelength is proved to cover 6-10 mm by changing the solenoid magnetic field from 0.4 T to 1.6 T. (author)

  16. Perspectives of imaging of single protein molecules with the present design of the European XFEL. Pt. 1. X-ray source, beamline optics and instrument simulations

    International Nuclear Information System (INIS)

    The Single Particles, Clusters and Biomolecules (SPB) instrument at the European XFEL is located behind the SASE1 undulator, and aims to support imaging and structure determination of biological specimen between about 0.1 μm and 1 μm size. The instrument is designed to work at photon energies from 3 keV up to 16 keV. This wide operation range is a cause for challenges to the focusing optics. In particular, a long propagation distance of about 900 m between X-ray source and sample leads to a large lateral photon beam size at the optics. The beam divergence is the most important parameter for the optical system, and is largest for the lowest photon energies and for the shortest pulse duration (corresponding to the lowest charge). Due to the large divergence of nominal X-ray pulses with duration shorter than 10 fs, one suffers diffraction from mirror aperture, leading to a 100-fold decrease in fluence at photon energies around 4 keV, which are ideal for imaging of single biomolecules. The nominal SASE1 output power is about 50 GW. This is very far from the level required for single biomolecule imaging, even assuming perfect beamline and focusing efficiency. Here we demonstrate that the parameters of the accelerator complex and of the SASE1 undulator offer an opportunity to optimize the SPB beamline for single biomolecule imaging with minimal additional costs and time. Start to end simulations from the electron injector at the beginning of the accelerator complex up to the generation of diffraction data indicate that one can achieve diffraction without diffraction with about 0.5 photons per Shannon pixel at near-atomic resolution with 1013 photons in a 4 fs pulse at 4 keV photon energy and in a 100 nm focus, corresponding to a fluence of 1023ph/cm2. This result is exemplified using the RNA Pol II molecule as a case study.

  17. Optics Concept for a Pair of Undulator Beamlines for MX*

    OpenAIRE

    Berman, L. E.; Allaire, M; Chance, M R; Hendrickson, W A; Héroux, A; Jakoncic, J.; Liu, Q.; Orville, A.M.; Robinson, H.H.; Schneider, D. K.; SHI, W.; Soares, A.S.; Stojanoff, V.; Stoner-Ma, D.; Sweet, R M

    2011-01-01

    We describe a concept for x-ray optics to feed a pair of macromolecular crystallography (MX) beamlines which view canted undulator radiation sources in the same storage ring straight section. It can be deployed at NSLS-II and at other low-emittance third-generation synchrotron radiation sources where canted undulators are permitted, and makes the most of these sources and beamline floor space, even when the horizontal angle between the two canted undulator emissions is as little as 1-2 mrad. ...

  18. Desing considerations for a fast modulator in a 'crossed undulator'

    International Nuclear Information System (INIS)

    The modulator, a short electromagnetic wiggler, can be used to generate a phase shift between the synchrotron radiation of the two undulators in a crossed undulator. The switching frequency between two polarization states can be as high as 10 Hz. This paper discusses some physical requirements for the modulator and a conceptual design of the magnet for a crossed undulator at the Aladdin storage ring (Synchrotron Radiation center, University of Wisconsin, Madison) as a prototype development for the Advanced Light Source (ALS) and the Advanced Photon Source (APS)

  19. First test results for an adjustable phase undulator

    International Nuclear Information System (INIS)

    An Adjustable Phase Undulator (APU) was installed and tested on the beamline 5 of the SPEAR storage ring. The APU has the same magnetic structure as a conventional adjustable gap undulator (AGU), but its magnetic field is varied by changing the longitudinal position between the rows of magnets, while keeping the gap between them fixed. The tests described here show that this undulator performs according to theoretical predictions and numerical models. The main reason to consider a phase adjustable design is the substantial reduction in size, complexity, and cost over comparable conventional designs. (author) 4 refs.; 3 figs

  20. UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

    International Nuclear Information System (INIS)

    We discuss the design and current status of experiments to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.

  1. Feasibility and electromagnetic analysis of a REBCO superconducting undulator

    Science.gov (United States)

    Kesgin, Ibrahim; Kasa, Matthew; Doose, Charles; Ivanyushenkov, Yury; Zhang, Yifei; Knoll, Alan; Brownsey, Paul; Hazelton, Drew; Welp, Ulrich

    2016-05-01

    Recent advances in second-generation (2G) high temperature superconducting (HTS) coated conductors (CCs) have made them very attractive for new applications such as undulators. In this paper, we have, for the first time, experimentally evaluated a design to validate applicability of 2G-HTS tapes for next generation undulator magnetic structures. A two-period undulator magnetic core was fabricated and 2G-HTS CCs were successfully wound onto the undulator core. The performance of the undulator magnetic structure was investigated and the highest engineering current density, J e, in such configuration reported yet was obtained. A new U-slit tape configuration was used to reduce the number of resistive joints and it was shown that with this new technique affordable levels of resistance values can be achieved for short length undulators. The ferromagnetic core was designed such as to accommodate winding the U-slit tapes. Test results indicated that the winding and the soldering procedures are successful and do not deteriorate the performance of the 2G-HTS tapes.

  2. Mapping the conformational landscape of a dynamic enzyme by multitemperature and XFEL crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Keedy, Daniel A.; Kenner, Lillian R.; Warkentin, Matthew; Woldeyes, Rahel A.; Hopkins, Jesse B.; Thompson, Michael C.; Brewster, Aaron S.; Van Benschoten, Andrew H.; Baxter, Elizabeth L.; Uervirojnangkoorn, Monarin; McPhillips, Scott E.; Song, Jinhu; Alonso-Mori, Roberto; Holton, James M.; Weis, William I.; Brunger, Axel T.; Soltis, S. Michael; Lemke, Henrik; Gonzalez, Ana; Sauter, Nicholas K.; Cohen, Aina E.; van den Bedem, Henry; Thorne, Robert E.; Fraser, James S.

    2015-09-30

    Determining the interconverting conformations of dynamic proteins in atomic detail is a major challenge for structural biology. Conformational heterogeneity in the active site of the dynamic enzyme cyclophilin A (CypA) has been previously linked to its catalytic function, but the extent to which the different conformations of these residues are correlated is unclear. Here we compare the conformational ensembles of CypA by multitemperature synchrotron crystallography and fixed-target X-ray free-electron laser (XFEL) crystallography. The diffraction-before-destruction nature of XFEL experiments provides a radiation-damage-free view of the functionally important alternative conformations of CypA, confirming earlier synchrotron-based results. We monitored the temperature dependences of these alternative conformations with eight synchrotron datasets spanning 100-310 K. Multiconformer models show that many alternative conformations in CypA are populated only at 240 K and above, yet others remain populated or become populated at 180 K and below. These results point to a complex evolution of conformational heterogeneity between 180-–240 K that involves both thermal deactivation and solvent-driven arrest of protein motions in the crystal. The lack of a single shared conformational response to temperature within the dynamic active-site network provides evidence for a conformation shuffling model, in which exchange between rotamer states of a large aromatic ring in the middle of the network shifts the conformational ensemble for the other residues in the network. Together, our multitemperature analyses and XFEL data motivate a new generation of temperature- and time-resolved experiments to structurally characterize the dynamic underpinnings of protein function.

  3. Using the X-FEL to understand X-ray Thomson scattering for partially ionized plasmas

    OpenAIRE

    Nilsen, J.; Johnson, W. R.; Cheng, K. T.

    2012-01-01

    For the last decade numerous researchers have been trying to develop experimental techniques to use X-ray Thomson scattering as a method to measure the temperature, electron density, and ionization state of high energy density plasmas such as those used in inertial confinement fusion. With the advent of the X-ray free electron laser (X-FEL) at the SLAC Linac Coherent Light Source (LCLS) we now have such a source available in the keV regime. One challenge with X-ray Thomson scattering experime...

  4. EMI suppression of klystron pulse power supply for XFEL/SPring-8

    International Nuclear Information System (INIS)

    The klystron modulator power source of XFEL/SPring-8 is requested the low electro-magnetic interference (EMI), in order to realize the high stable beam by the feedback loops of high-precision beam monitors. We suppressed the EMI-noise by monocoque structure of the solid iron chassis, the eliminating the DC core bias circuit for the pulse transformer, and the co-axial pare noise filter. To estimate the effect of the noise filter, we measured the conducted noise on the heater power line. The thyratron noise was suppressed to about 10Vpk-pk, and would not interfere to the beam monitor. (author)

  5. High Energy/Intensity Lasers for HED Science at European XFEL

    OpenAIRE

    Priebe, Gerd; Nakatsutsumi, Motoaki; Thorpe, Ian; Mueller, Benjamin; Pelka, Alexander; Appel, Karen; TSCHENTSCHER, Thomas; Lederer, Maximilian

    2014-01-01

    Free-electron laser facilities provide new applications in the field of high-pressure research including planetary materials. The European X-ray Free Electron Laser (XFEL) in Hamburg will start user operation in 2017 and will provide photon energies of up to 25 keV. With a photon flux of about $10^{12}$ photons/pulse, with a pulse duration of 2–100 fs and a repetition rate of up to 4.5 MHz during 600 μs long bursts with a repetition rate of 10 Hz, rendering up to 27000 pulses per second, this...

  6. Interferometry using undulator sources (invited, abstract)

    Science.gov (United States)

    Beguiristain, R.; Goldberg, K. A.; Tejnil, E.; Bokor, J.; Medecki, H.; Attwood, D. T.; Jackson, K.

    1996-09-01

    Optical systems for extreme ultraviolet (EUV) lithography need to use optical components with subnanometer surface figure error tolerances to achieve diffraction-limited performance [M.D. Himel, in Soft X-Ray Projection Lithography, A.M. Hawryluk and R.H. Stulen, eds. (OSA, Washington, D.C., 1993), 18, 1089, and D. Attwood et al., Appl. Opt. 32, 7022 (1993)]. Also, multilayer-coated optics require at-wavelength wavefront measurement to characterize phase effects that cannot be measured by conventional optical interferometry. Furthermore, EUV optical systems will additionally require final testing and alignment at the operational wavelength for adjustment and reduction of the cumulative optical surface errors. Therefore, at-wavelength interferometric measurement of EUV optics will be the necessary metrology tool for the successful development of optics for EUV lithography. An EUV point diffraction interferometer (PDI) has been developed at the Center for X-Ray Optics (CXRO) and has been already in operation for a year [K. Goldberg et al., in Extreme Ultra Lithography, D.T. Attwood and F. Zernike, eds. (OSA, Washington, D.C., 1994), K. Goldberg et al., Proc. SPIE 2437, to be published, and K. Goldberg et al., J. Vac. Sci. Technol. B 13, 2923 (1995)] using an undulator radiation source and coherent optics beamline at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. An overview of the PDI interferometer and some EUV wavefront measurements obtained with this instrument will be presented. In addition, future developments planned for EUV interferometry at CXRO towards the measurement of actual EUV lithography optics will be shown.

  7. Design of an x-ray free electron laser undulator

    International Nuclear Information System (INIS)

    An undulator designed to be used for an x-ray free electron laser has to meet a set of stringent requirements. With no optical cavity, an x-ray FEL operates in the single pass Self Amplified Spontaneous Emission (SASE) mode; an electron macropulse is microbunched by an undulator and the radiation it creates. The microbunched pulse emits spontaneous radiation and coherent FEL radiation, whose power may reach saturation in a sufficiently long and perfect undulator. The pulse must have low emittance and high current, and its trajectory in the undulator must keep the radiation and the pulse together with a very high degree of overlap. We shall consider the case of the Linear Coherent Light Source (LCLS) FEL project at SLAC, which is intended to create 1.5 A x-rays using an electron beam with 15 GeV energy, 1.5π mm-mrad normalized emittance, 3400 A peak current, and 280 fsec FWHM bunch duration. We find that this 65 μm rms diameter beam must overlap its radiation with a walkoff of no more than 5 μm for efficient gain. This places severe limitations on the magnetic field errors and other mechanical tolerances. The following is a discussion of the undulator design, specifications, alignment, engineering, and beam position monitoring we plan to implement for the LCLS X-ray FEL

  8. Design of an x-ray free electron laser undulator

    International Nuclear Information System (INIS)

    An undulator designed to be used for an x-ray free electron laser has to meet a set of stringent requirements. With no optical cavity, an x-ray FeL operates in the single pass Self Amplified Spontaneous Emission (SASE) mode; an electron macropulse is microbunched by an undulator and the radiation it creates. The microbunched pulse emits spontaneous radiation and coherent FEL radiation, whose power may reach saturation in a sufficiently long and perfect undulator. The pulse must have low emittance and high current, and its trajectory in the undulator must keep the radiation and the pulse together with a very high degree of overlap. The authors shall consider the case of the Linear Coherent Light Source (LCLS) FEL project at SLAC, which is intended to create 1.5 angstrom x-rays using an electron beam with 15 GeV energy, 1.5π mm-mrad normalized emittance, 3,400 A peak current, and 280 fsec FWHM bunch duration. They find that this 65 microm rms diameter beam must overlap its radiation with a walkfoff of no more than 5 microm for efficient gain. This places severe limitations on the magnetic field errors and other mechanical tolerances. The following is a discussion of the undulator design, specifications, alignment, engineering, and beam position monitoring they plan to implement for the LCLS X-ray FEL

  9. Improved crystal orientation and physical properties from single-shot XFEL stills

    International Nuclear Information System (INIS)

    X-ray free-electron laser crystallography relies on the collection of still-shot diffraction patterns. New methods are developed for optimal modeling of the crystals’ orientations and mosaic block properties. X-ray diffraction patterns from still crystals are inherently difficult to process because the crystal orientation is not uniquely determined by measuring the Bragg spot positions. Only one of the three rotational degrees of freedom is directly coupled to spot positions; the other two rotations move Bragg spots in and out of the reflecting condition but do not change the direction of the diffracted rays. This hinders the ability to recover accurate structure factors from experiments that are dependent on single-shot exposures, such as femtosecond diffract-and-destroy protocols at X-ray free-electron lasers (XFELs). Here, additional methods are introduced to optimally model the diffraction. The best orientation is obtained by requiring, for the brightest observed spots, that each reciprocal-lattice point be placed into the exact reflecting condition implied by Bragg’s law with a minimal rotation. This approach reduces the experimental uncertainties in noisy XFEL data, improving the crystallographic R factors and sharpening anomalous differences that are near the level of the noise

  10. A Stable 200TW / 1Hz Ti:sapphire laser for driving full coherent XFEL

    Science.gov (United States)

    Xu, Yi; Lu, Jun; Li, Wenkai; Wu, Fenxiang; Li, Yanyan; Wang, Cheng; Li, Zhaoyang; Lu, Xiaoming; Liu, Yanqi; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2016-05-01

    Basic features of the ultra-short Ti:sapphire laser for driving compact X-ray free electron laser (XFEL) seeded by laser-driven high harmonic generation (HHG) at SIOM (Shanghai, China) is presented. The laser system consists of four-stage Ti:sapphire amplifiers and can produce 8 J energy at 1 Hz repetition rate after the final power amplifier. The best shot-to-shot energy fluctuation is as low as 0.54% in rms value, which is a desirable characteristic for driving stable electron acceleration and HHG seed. After compression, maximal pulse energy of 5.6 J and pulse duration of 27 fs can be obtained, the corresponding pulse peak power is above 200 TW. To achieve full coherent XFEL, the amplified chirped laser beam is split into two beams after the final power amplifier. After compression in two independent compressors, the two laser beams can be used to drive laser wakefield acceleration (LWFA) and HHG respectively. The benefit of such a scheme is to improve the timing jitter and achieve all-optical synchronization between the electron beam and HHG seed in the near future.

  11. Development status of the beam diagnostic system for XFEL/SPring-8

    International Nuclear Information System (INIS)

    The XFEL facility requires sub-μm resolution beam position monitors (BPM), screen monitors with a resolution of less than 10 μm, high-speed beam-charge monitors and a temporal structure measurement system with a resolution of less than 10 fs. We developed an rf cavity BPM that uses the TM110 mode at 4760 MHz. The estimated position resolution was 0.2 μm. For the screen monitor, we designed a custom lens system having a 2 μm resolution and variable magnifications from 1 to 4. For the charge measurement, we developed a high-speed differential current transformer (CT). The rise time of the CT signal was 0.2 ns and common-mode noise was considerably reduced. To measure the temporal beam structure, we developed a C-band (5712 MHz) transverse deflecting cavity that has a disk-loaded backward traveling wave structure. This cavity can resolve a beam into a few fs fragments. Thus, the beam-diagnostic system satisfies the demands of the XFEL accelerator. (author)

  12. Double-focusing mixing jet for XFEL study of chemical kinetics

    International Nuclear Information System (INIS)

    A novel method for time-resolved study of chemical kinetics using a windowless mixing jet at an X-ray free-electron laser (XFEL) is described and demonstrated. The short mixing time gives a time resolution of about 250 µs; the design introduces controllable delays after the initiation of a chemical reaction, allowing the possibility for detection of transient structures by an XFEL beam pulse. Applications may include time-resolved enzyme–substrate imaging or protein folding. Several liquid sample injection methods have been developed to satisfy the requirements for serial femtosecond X-ray nanocrystallography, which enables radiation-damage-free determination of molecular structure at room temperature. Time-resolved nanocrystallography would combine structure analysis with chemical kinetics by determining the structures of the transient states and chemical kinetic mechanisms simultaneously. A windowless liquid mixing jet device has been designed for this purpose. It achieves fast uniform mixing of substrates and enzymes in the jet within 250 µs, with an adjustable delay between mixing and probing by the X-ray free-electron laser beam of up to 1 s for each frame of a ‘movie’. The principle of the liquid mixing jet device is illustrated using numerical simulation, and experimental results are presented using a fluorescent dye

  13. Phase error reduction in superconductive undulators using induction shimming

    International Nuclear Information System (INIS)

    As shown in a first proof of principle experiment, induction shimming can constitute a simple and efficient method of increasing the field quality of superconductive undulators. Although previous measurements on a single undulator half were successful in giving a qualitative understanding on hysteresis in the shim coils, it was found that the measurement setup needs improvement for meaningful calculations of the phase error reduction. Presented here are the first results on phase error reduction with induction shimming, using a measurement setup with improved accuracy. Theoretical results on the coupling between shim coils, important for the function of the shim system and for an extension to full length undulators, are also presented in this contribution.

  14. Photon energy tunability of the advanced photon source undulators

    International Nuclear Information System (INIS)

    At a fixed storage ring energy, the energy of the harmonics of an undulator can be shifted or open-quote tunedclose quotes by changing the magnet gap of the device. The possible photon energy interval spanned in this way depends on the undulator period, minimum closed gap, minimum acceptable photon intensity and storage ring energy. The minimum magnet gap depends directly on the stay-clear particle beam aperture required for storage ring operation. The tunability of undulators planned for the Advanced Photon Source with first harmonic photon energies in the range of 5-20 keV is discussed. The results of an analysis used to optimize the APS ring energy is presented and tunability contours and K-values are given for two typical classes of devices

  15. Electron spectra and coherence of radiation in undulators

    CERN Document Server

    Bulyak, Eugene

    2015-01-01

    Most bright sources of the radiation in hard x-ray and gamma--ray regions are undulator sources and Compton based ones. These sources are ultimate for production of polarized positrons necessary for future linear colliders ILC, CLIC. We developed a novel method for evaluating the energy spectrum of electrons emitting the undulator- and the inverse Compton radiation. The method based on Poisson weighted superposition of electron states is applicable for whole range of the emission intensity per electron pass through the driving force, from much less than unity emitted photons (Compton sources) to many photons emitted (undulators), and for any energy of the photons. The method allows for account contributions in the energy spread both from the Poisson statistics and diffusion due to recoils. The theoretical results were confirmed by simulations. The electron energy spectrum was used for evaluation of the on-axis density of photons and their coherency making use of the `carrier--envelope' presentation for the em...

  16. Superradiance in an undulator in dual resonance mode

    Science.gov (United States)

    Bogdankevich, L. S.; Gelkhviidze, L. K.; Ivanov, V. S.; Krementsov, S. I.; Rayzer, M. D.; Rukhadze, A. A.; Fedotov, A. V.

    1986-01-01

    The emission of a relativistic electron beam in a linearly polarized undulator magnetic field is investigated experimentally and theoretically. The Terek-I high current accelerator was employed as the electron beam injector. A spatially periodic magnetic field was formed by a system of copper rings within the external pulse magnetic field. The resonance conditions for the longitudinal and transverse components of the magnetic field are investigated. Current transmission is found to be strongly dependent on the angle between the axis of the undulator and the axis of the solenoid. A system of equations is derived for the movement of a relativistic electron in the magnetic field of the undulator. The experimentally observed values of the resonant longitudinal magnetic field, the width of the resonant region, the transverse velocity of the electrons, and the radiation line width are explained analytically.

  17. Simulation of electron trajectory in bulk HTSC staggered array undulator

    International Nuclear Information System (INIS)

    To realize short-period high-magnetic-field undulator, we have proposed an undulator using bulk high temperature superconductor in a staggered array structure. To investigate the effect of the longitudinal solenoid field on the electron beam trajectory and find out the optimum value of the solenoid field, the magnetic field near the center of this undulator was modeled and the trajectory of the single electron was calculated. As a result, we found that the stronger solenoid field worked as a stronger convergence force. However, the optimum value was not able to be determined by the result of trajectory calculation because the stronger field changes the spectrum of the radiation from the beam. (author)

  18. Coherent harmonic production using a two-section undulator FEL

    Energy Technology Data Exchange (ETDEWEB)

    Jaroszynski, D.A. [Commissariat a l`Energie, Bruyeres-le-Chatel (France); Prazeres, R.; Glotin, F. [Centre Universitaire Paris-Sud (France)] [and others

    1995-12-31

    We present measurements and a theoretical analysis of a new method of generating harmonic radiation in a free-electron laser oscillator with a two section undulator in a single optical cavity. To produce coherent harmonic radiation the undulator is arranged so that the downstream undulator section resonance frequency matches a harmonic of the upstream undulator. Both the fundamental and the harmonic optical fields evolve in the same optical cavity and are coupled out with different extraction fractions using a hole in one of the cavity mirrors. We present measurements that show that the optical power at the second and third harmonic can be enhanced by more than an order of magnitude in this fundamental/harmonic configuration. We compare the production of harmonic radiation of a two sectioned fundamental/harmonic undulator with that produced from a FEL operating at its highest efficiency with a step-tapered undulator, where the bunching at the end of the first section is very large. We examine, the dependence of the harmonic power on the intracavity power by adjusting the optical cavity desynchronism, {delta}L. We also examine the evolution of the fundamental and harmonic powers as a function of cavity roundtrip number to evaluate the importance of the small signal gain at the harmonic. We compare our measurements with predictions of a multi-electron numerical model that follows the evolution of fundamental and harmonic power to saturation. This fundamental/harmonic mode, of operation of the FEL may have useful applications in the production of coherent X-ray and VUV radiation, a spectral range where high reflectivity optical cavity mirrors are difficult or impossible to manufacture.

  19. Computational Research on Modular Undulating Fin for Biorobotic Underwater Propulsor

    Institute of Scientific and Technical Information of China (English)

    Yong-hua Zhang; Lai-bing Jia; Shi-wu Zhang; Jie Yang; K.H.Low

    2007-01-01

    Biomimetic design employs the principles of nature to solve engineering problems.Such designs which are hoped to be quick,efficient,robust,and versatile,have taken advantage of optimization via natural selection.In the present research.an environment-friendly propulsion system mimicking undulating fins of stingray was built.A non-conventional method was considered to model the flexibility of the fins of stingray.A two-degree-of-freedom mechanism comprised of several linkages was designed and constructed to mimic the actual flexible fin.The driving linkages were used to form a mechanical fin consisting of several fin segments,which are able to produce undulations,similar to those produced by the actual fins.Owing to the modularity of the design of the mechanical fin,various undulating patterns can be realized.Some qualitative observations,obtained by experiments,predicted that the thrusts produced by the mechanical fin are different among various undulating patterns.To fully understand this experimental phenomenon is very important for better performance and energy saving for our biorobotic underwater propulsion system.Here,four basic undulating patterns of the mechanical fin were performed using two-dimensional unsteady computational fluid dynamics(CFD)method.An unstructured,grid-based,unsteady Navier-Stokes solver with automatic adaptive re-meshing was used to compute the unsteady flow around the fin through twenty complete cycles.The pressure distribution on fin surface was computed and integrated to provide fin forces which were decomposed into lift and thrust.The pressure force and friction force were also computed throughout the swimming cycle.Finally,vortex contour maps of these four basic fin undulating patterns were displayed and compared.

  20. Commissioning of the Delta Polarizing Undulator at LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Nuhn, Heinz-Dieter

    2015-09-25

    The Linac Coherent Light Source (LCLS) generates linearly polarized, intense, high-brightness x-ray pulses from planar fixed-gap undulators. While the fixed-gap design supports a very successful and tightly controlled alignment concept, it provides only limited taper capability (up to 1% through canted pole and horizontal position adjustability) and lacks polarization control. The latter is of great importance for soft x-ray experiments. A new 3.2-m-long compact undulator (based on the Cornell University Delta design) has been developed and installed in place of the last LCLS undulator segment (U33) in October 2014. This undulator provides full control of the polarization degree and K value. Used on its own, it produces fully polarized radiation in the selected state (linear, circular or elliptical) but at low intensity. To increase the output power by orders of magnitude, the electron beam is micro-bunched by several (~10) of the upstream LCLS undulator segments operated in the linear FEL regime. As unavoidable by-product, this microbunching process produces moderate amounts of horizontally linear polarized radiation which mixes with the radiation produced by the Delta undulator. This unwanted radiation component has been greatly reduced by the reverse taper configuration, as suggested by E. Schneidmiller and M. Yurkov. Full elimination of the linear polarized component was achieved through spatial separation combined with transverse collimation. The paper describes these and other methods tested during commissioning. It also presents results of polarization measurements showing high degrees of circular polarization in the soft x-ray wavelength range (500 eV - 1500 eV).

  1. U10.0 Undulator conceptual design report

    International Nuclear Information System (INIS)

    The U10.0 Undulator described here is a 43 period, 10 cm period, 4.5 meter long insertion device. Designed for the Advanced Light Source (ALS) storage ring at the Lawrence Berkeley Laboratory. This insertion device will provide high brightness, quasi-monochromatic radiation in the 5-950 eV energy range. This conceptual design report includes sections on: parameter development, spectral performance, and accelerator requirements, physics specifications and the detailed conceptual design of the magnetic structure, the support/drive systems, the insertion device control system, the vacuum system, and installation for the U10.0 Undulator

  2. Numerical modeling of shoreline undulations part 1: Constant wave climate

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg; Fredsøe, Jørgen

    2013-01-01

    This paper presents a numerical study of the non-linear development of alongshore undulations up to fully developed quasi-steady equilibrium. A numerical model which describes the longshore sediment transport along arbitrarily shaped shorelines is applied, based on a spectral wave model, a depth...... integrated flow model, a wave-phase resolving sediment transport description and a one-line shoreline model.First the length of the shoreline undulations is determined in the linear regime using a stability analysis. Next the further evolution from the linear to the fully non-linear regime is described. In...

  3. Research on the Undulator Used for PKU-FEL

    CERN Document Server

    Lu, Huihua; Dai, Jianping; Li, Yanan; Shi, Caitu; Yang Yu Feng; Zhuang, Jiejia

    2004-01-01

    A 5m-long combined function undulator used for the Peking University Infrared SASE FEL facility (PKU-FEL) is currently under construction at IHEP, and a 10 period prototype has already been developed. This paper describes the design study of the undulator, which is a hybrid planar magnet structure with extra focusing. The results of magnetic measurements performed on the prototype are also reported and discussed, and it demonstrates that the proposed combined function magnet structure is very promising for the use in the SASE FEL at Peking University.

  4. Experimental Study For The Feasibility Of A Crystalline Undulator

    CERN Document Server

    Bellucci, S; Biryukov, V M; Chesnokov, Yu A; Dabagov, S B; Giannini, G; Guidi, V; Ivanov, Y M; Kotov, V I; Maisheev, V A; Malagu, C; Martinelli, G; Petrunin, A A; Skorobogatov, V V; Stefancich, M; Vincenzi, D; Chesnokov, Yu.A.; Ivanov, Yu.M.

    2003-01-01

    We present an idea for creation of a crystalline undulator and report its first realization. One face of a silicon crystal was given periodic micro-scratches (trenches) by means of a diamond blade. The X-ray tests of the crystal deformation due to given periodic pattern of surface scratches have shown that a sinusoidal shape is observed on both the scratched surface and the opposite (unscratched) face of the crystal, that is, a periodic sinusoidal deformation goes through the bulk of the crystal. This opens up the possibility for experiments with high-energy particles channeled in crystalline undulator, a novel compact source of radiation.

  5. Coherent effects of a macro-bunch in an undulator

    CERN Document Server

    Dohlus, M; Limberg, T

    2000-01-01

    The longitudinal radiative force of an electron bunch moving in an undulator has been investigated in [1] assuming an 1D density distribution. To obtain the contribution of pure curvature effects and to avoid singular fields, the 1D linear motion field was subtracted. To relate these results to the 3D case we present analytical and numerical field calculations using the field solver of TRAFIC4. The 1D and 3D cases have been calculated in the transient regime, the steady-state regime and the steady-state regime averaged over one undulator period for the 1 GeV parameter set of the TESLA FEL.

  6. Calculations of magnetic field errors caused by mechanical accuracy at infra-red undulator construction

    International Nuclear Information System (INIS)

    At the Joint Institute for Nuclear Research (Dubna) the electromagnetic undulator with maximal magnetic field 1.2 T and 40 cm period is under development. The computer models for the undulator magnet system were realized on the basis of POISSON and RADIA codes. The undulator magnetic field imperfections due to the design errors were simulated by the models

  7. Spontaneous radiation from relativistic electrons in a tapered Apple-II undulator

    International Nuclear Information System (INIS)

    This paper presents most properties of radiation from a tapered Apple-II undulator. The study demonstrates that tapering an Apple-II undulator can broaden the harmonic bandwidth and the performance of polarization is also excellent at the broadened energy range. So Apple-II undulator can be tapered to provide more convenience for energy scan experiment. (authors)

  8. Test of an undulated vacuum chamber for the ISR

    CERN Multimedia

    1975-01-01

    This picture shows mechanical tests of an undulated vacuum chamber for downstream arms of ISR intersections. This chamber, made of 0.3 mm thick inconel, had inner dimensions of 150 mm by 50 mm. The deflection under vacuum is measured by dial gauges. On the left one sees the large vessel where vacuum chambers were tested at pressures above atmospheric pressure.

  9. Bionic asymmetry: from amiiform fish to undulating robotic fins

    Institute of Scientific and Technical Information of China (English)

    HU TianJiang; SHEN LinCheng; LOW K.H.

    2009-01-01

    Similar to bionic non-smooth which has been successfully applied in anti-resistance and anti-adhesion, bionic asymmetry is also an inherent property of biological systems and is worth exploring for con-ceivable pragmatic applications. Therefore, bionic asymmetry for undulations is of main interest in this paper. We initially investigate bionic asymmetry with a case study of the undulating robotic fin, RoboGnilos, which evolved from the long dorsal fin of Gymnarchus niloticus in the amiiforrn mode. Since the performance of the pre-existing undulating fins is hardly satisfactory, we obtain bionic in-spirations of undulatory asymmetry through observations and measurements on the specimen of G. niloticus, to improve upon the performance. Consequently, the newly acquired innovation for bionic asymmetry is incorporated into the previously derived kinematics model, and also applied to the ex-perimental prototype. Both computational and experimental results verify that bionic asymmetric un-dulation generates better propulsion performance (in terms of linear velocity and efficiency) than the traditional symmetric modes with the same undulatory parameters.

  10. Overview of undulators and wigglers for the NSLS

    International Nuclear Information System (INIS)

    This summary is designed to present to the NSLS user community the possible options for wigglers and undulators. The desire is to make it possible for every user to respond to the request by the NSLS for guidance in insertion device development so that it can best serve their scientific interests. There are many options, each with its own advantages and disadvantages, as well as certain restrictions imposed by the parameters of the NSLS storage rings. The NSLS is asking for input in two areas. First, we must decide on the instrumentation to be developed for the high field superconducting wiggler beam lines and for the hybrid permanent magnet wiggler lines. Secondly, the long-range plans for additional insertion devices are now under discussion. Choices must be made between the large number of different magnets which can be built. To facilitate user response, we provide a review of the properties of wigglers and undulators, introducing the basic concepts and defining the fundamental parameters. A detailed account of the brightness of the undulator source is presented and the insertion devices already under construction for the x-ray and VUV rings are discussed. We describe the suitability of certain proposed undulators for the generation of soft x-rays (5 to 50A), and harder x-rays

  11. The LCLS Undulator Beam Loss Monitor Readout System

    Energy Technology Data Exchange (ETDEWEB)

    Dusatko, John; Browne, M.; Fisher, A.S.; Kotturi, D.; Norum, S.; Olsen, J.; /SLAC

    2012-07-23

    The LCLS Undulator Beam Loss Monitor System is required to detect any loss radiation seen by the FEL undulators. The undulator segments consist of permanent magnets which are very sensitive to radiation damage. The operational goal is to keep demagnetization below 0.01% over the life of the LCLS. The BLM system is designed to help achieve this goal by detecting any loss radiation and indicating a fault condition if the radiation level exceeds a certain threshold. Upon reception of this fault signal, the LCLS Machine Protection System takes appropriate action by either halting or rate limiting the beam. The BLM detector consists of a PMT coupled to a Cherenkov radiator located near the upstream end of each undulator segment. There are 33 BLMs in the system, one per segment. The detectors are read out by a dedicated system that is integrated directly into the LCLS MPS. The BLM readout system provides monitoring of radiation levels, computation of integrated doses, detection of radiation excursions beyond set thresholds, fault reporting and control of BLM system functions. This paper describes the design, construction and operational performance of the BLM readout system.

  12. Beam cooling by using laser-undulator beat wave

    International Nuclear Information System (INIS)

    Non-Hamiltonian manipulation of internal structure of phase space of charged particle beams can result in much faster cooling than the conventional stochastic cooling. The longitudinal emittance reduction is accomplished by the ponderomotive force of the beat between the undulator and the laser adjusted appropriate in its broadband spectrum through feedback at each turn. (author)

  13. Thermal undulations of quasi-spherical vesicles stabilized by gravity

    DEFF Research Database (Denmark)

    Henriksen, Jonas Rosager; Ipsen, John Hjorth

    2002-01-01

    The classical treatment of quasi-spherical vesicle undulations has, in the present work, been reviewed and extended to systems, which are affected by a gravitational field caused by a density difference across the membrane. The effects have been studied by the use of perturbation theory leading to...

  14. Effect of 'effective cooling' in the EH-UNDULATIVE systems

    International Nuclear Information System (INIS)

    The theory of the systems for forming of electron bunches with especially small energy spread (EH-coolers) is developed. Therein, real arrangement of the acted EH-undulative fields is taking into account in the considered theoretical model. It is shown that this could be important for accomplishing of quantitative analysis EH-coolers of the discussed type

  15. Measurement, sorting and tuning of LCLS undulator magnets

    International Nuclear Information System (INIS)

    Currently, a Linac Coherent Light Source (LCLS) prototype undulator is under construction. The prototype is a 3.4-m-long hybrid-type undulator with fixed gap of 6 mm. The period length is 30 mm and the number of poles is 226. For this undulator, 450 NdFeB magnet blocks are used. This project does not have demanding requirements for multipole component errors, but the field strength at x=0 should be as precise as possible to provide proper particle steering and phase errors. The first set of magnetic blocks has been measured. The strength and direction of magnetization of the magnet blocks are measured using a Helmholtz coil system. In addition to this, Hall probe measurements are performed for magnet blocks while they are mounted in a specially designed cassette with vanadium-permendur poles. The magnet blocks will be sorted using these data to minimize errors. Computer simulations show that magnets may be sorted in decreasing strengths with little or no additional tuning of the undulators

  16. CSR effect at XFEL-to-storage ring beam transport line, SPring-8

    International Nuclear Information System (INIS)

    A 300-meter long beam transport line will be built from the XFEL C-band linac to the existing 8 GeV storage ring at the SPring-8. The beam transport line is supposed to deliver femtosecond electron bunches with high peak current, being composed of 14 bending magnets and quadrupoles. Current status of the transport line construction plan is briefly presented. Since Coherent Synchrotron Radiation (CSR) could degrade a beam quality in such a transport line with multiple bends, tracking simulation on the effect has been employed to analyze the effect in the transport line. As a result, it was found that the CSR effect would not be negligible unless some modification would be made to either an electron bunch distribution or a lattice of the beam transport line. The numerical result on the CSR effect as well as a proposal to compress femtosecond bunches by positively utilizing CSR effect is shown. (author)

  17. XFEL resonant photo-pumping of dense plasmas and dynamic evolution of autoionizing core hole states

    Science.gov (United States)

    Rosmej, F. B.; Moinard, A.; Renner, O.; Galtier, E.; Lee, J. J.; Nagler, B.; Heimann, P. A.; Schlotter, W.; Turner, J. J.; Lee, R. W.; Makita, M.; Riley, D.; Seely, J.

    2016-03-01

    Similarly to the case of LIF (Laser-Induced Fluorescence), an equally revolutionary impact to science is expected from resonant X-ray photo-pumping. It will particularly contribute to a progress in high energy density science: pumped core hole states create X-ray transitions that can escape dense matter on a 10 fs-time scale without essential photoabsorption, thus providing a unique possibility to study matter under extreme conditions. In the first proof of principle experiment at the X-ray Free Electron Laser LCLS at SCLAC [Seely, J., Rosmej, F.B., Shepherd, R., Riley, D., Lee, R.W. Proposal to Perform the 1st High Energy Density Plasma Spectroscopic Pump/Probe Experiment”, approved LCLS proposal L332 (2010)] we have successfully pumped inner-shell X-ray transitions in dense plasmas. The plasma was generated with a YAG laser irradiating solid Al and Mg targets attached to a rotating cylinder. In parallel to the optical laser beam, the XFEL was focused into the plasma plume at different delay times and pump energies. Pumped X-ray transitions have been observed with a spherically bent crystal spectrometer coupled to a Princeton CCD. By using this experimental configuration, we have simultaneously achieved extremely high spectral (λ/δλ ≈ 5000) and spatial resolution (δx≈70 μm) while maintaining high luminosity and a large spectral range covered (6.90 - 8.35 Å). By precisely measuring the variations in spectra emitted from plasma under action of XFEL radiation, we have successfully demonstrated transient X- ray pumping in a dense plasma.

  18. A front-end stage with signal compression capability for XFEL detectors

    Science.gov (United States)

    Nasri, B.; Fiorini, C.; Grande, A.; Erdinger, F.; Fischer, P.; Porro, M.

    2015-01-01

    In this work, we present a front-end stage with signal compression capability to be used in detectors for the new European XFEL in Hamburg. This front-end is an alternative solution under study for the DEPFET Sensor with Signal Compression (DSSC) detection system for the European XFEL. The DEPFET sensor of the DSSC project has a high dynamic range and very good noise performance. The high gain for small collected charge and the compression for large signals will provide both desired features of single photon detection capability and wide dynamic range. However, manufacturing of the DEPFET sensor requires a sophisticated processing technology with a relatively long time fabrication process. Accordingly, an alternative solution, namely Day-0 solution, was introduced as an approach characterized not by the best performance of the DEPFET, but available in a shorter time to allow first beam tests and experiments. The alternative sensor is made of mini Silicon Drift Detector (mini-SDD) and the compression behavior is obtained from the front-end on the readout ASIC and not by the transistor integrated in the silicon sensor, as in the DEPFET. The first version of corresponding front-end of the Day-0 solution has been realized based on an input PMOSFET transistor placed on the readout chip. This simple front-end proved the working principle of the proposed compression technique and the desired noise performance. In this paper, an improved version of the Day-0 front-end is presented. In the new prototype, the current gain of the front-end stage has been increased by factor of 1.8, the total input capacitance (SDD+PMOSFET) has been reduced by factor of 2 with respect to the previous prototype and consequently the noise performance has been improved. Moreover, by introducing selectable extra branches in parallel with the main one, the compression behavior of the front-end can be tuned based on desired dynamic range.

  19. Design of an X-ray FEL undulator

    International Nuclear Information System (INIS)

    An undulator designed to be used for an x-ray free electron laser has to meet a set of stringent requirements. With no optical cavity, an x-ray FEL operates in the single pass Self Amplified Spontaneous Emission (SASE) mode; an electron macropulse is microbunched by an undulator and the radiation it creates. The microbunched pulse emits spontaneous radiation and coherent FEL radiation, whose power may reach saturation in a sufficiently long and perfect undulator. The pulse must have low emittance and high current, and its trajectory in the undulator must keep the radiation and the pulse together with a very high degree of overlap. In this paper we use the case of the Linear Coherent Light Source (LCLS) x-ray free electron laser to illustrate design concepts for long free electron laser undulators. The LCLS is intended to create 1.5 A x-rays using an electron beam with 15 GeV energy, 1.5π mm-mrad normalized emittance, 3400 A peak current, and 280 fsec FWHM bunch duration. According to our simulations, this 2σr=65 mm rms diameter beam must overlap its radiation with a walkoff of no more than 5 μm RMS per 11.7 meter field gain length for efficient gain. The energy spread of the beam is σE=0.0002 Ee. This places severe limitations on the magnetic field errors and on mechanical tolerances. In this paper we shall discuss how to meet these requirements

  20. Undulator physics and coherent harmonic generation at the MAX-lab electron storage ring

    International Nuclear Information System (INIS)

    This work presents the undulator and harmonic generation project at the electron storage ring MAX-lab at University of Lund. The theory of undulator radiation, laser coherent harmonic generation, optical klystron amplifiers and FELs is treated in one uniform way, with complete solutions of the necessary equations. The permanent magnet undulator is described in some detail, along with the installation of the undulator in the storage ring. Details regarding the emitted radiation, the electron beam path in the undulator and other results are analysed. Finally harmonic generation using a Nd:YAG laser and the creation of coherent photons at the third harmonic (355 nm) is described. (author)

  1. APPLE-II type quasi-periodic variably polarizing undulator at HiSOR

    International Nuclear Information System (INIS)

    A newly constructed quasi-periodic APPLE-II undulator was installed in the HiSOR ring at Hiroshima Synchrotron Radiation Center, Hiroshima University during the summer shutdown period in 2011. This 1.8 m-long undulator has a period length of 78 mm. In this article, the mechanism of magnetic field generation for various polarization modes of APPLE undulator, the principle of quasi-periodic undulator and the performance of HiSOR QP-APPLE-II undulator are described. (author)

  2. Improvements of the undulator spectral performance by compensating the backing beam deflection

    CERN Document Server

    Wang, C; Chang, L H; Chang, C H; Fan, T C; Bach, H; Blomqvist, I

    2002-01-01

    This study thoroughly examines how the backing beam deflection affects the undulator spectral performance. Reduction of the undulator spectral intensity owing to backing beam deflection is analytically evaluated based on plane-wave approximation. The results reveal that the amplitude and the slope of the backing beam deflection affect the undulator spectral performance. Provided is a novel figure-of-merit, rms of the regressed accumulated gap deviation, to determine the backing beam deflection budget. An example of a 3.9 m undulator supporting carriage mounted with 50-mm period length undulator magnet (U5) under a maximum magnetic loading of 5 metric tons at a minimum operating gap of 14 mm, is provided. Its mechanical features are first examined via 3D commercial finite element code ANSYS that concludes the backing beam deflection is influenced heavily by the rigidity of the undulator support frames. Examining the corresponding spectral performance shows that significantly diminishing the undulator spectral ...

  3. Design and performance of the APPLE-Knot undulator

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Fuhao [Department of Physics, State Key Laboratory of Surface Physics, and Laboratory of Advanced Materials, Fudan University, 2005 Songhu Road, Shanghai 200438, People’s Republic of (China); Chang, Rui [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, People’s Republic of (China); Zhou, Qiaogen; Zhang, Wei [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 239 Zhangheng Road, Shanghai 201204, People’s Republic of (China); Ye, Mao [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, People’s Republic of (China); Sasaki, Shigemi [Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Hiroshima 739-0046 (Japan); Qiao, Shan, E-mail: qiaoshan@mail.sim.ac.cn [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, People’s Republic of (China); School of Physical Science and Technology, ShanghaiTech University, 319 Yueyang Road, Shanghai 200031, People’s Republic of (China)

    2015-06-09

    The design and performance of the Apple-Knot undulator which can generate photons with arbitrary polarization and low on-axis heat load are presented. Along with the development of accelerator technology, synchrotron emittance has continuously decreased. This results in increased brightness, but also causes a heavy heat load on beamline optics. Recently, optical surfaces with 0.1 nm micro-roughness and 0.05 µrad slope error (r.m.s.) have become commercially available and surface distortions due to heat load have become a key factor in determining beamline performance, and heat load has become a serious problem at modern synchrotron radiation facilities. Here, APPLE-Knot undulators which can generate photons with arbitrary polarization, with low on-axis heat load, are reported.

  4. Training and magnetic field measurements of the ANKA superconducting undulator

    International Nuclear Information System (INIS)

    In 2011 a 1.5 m long superconducting undulator with a period length of 15mm is scheduled to be installed in ANKA. This insertion device is planned to be the light source of the new beamline NANO for high resolution X-ray diffraction. The key specifications of the system are an undulator parameter K higher than 2 (for a magnetic gap of 5mm) and a phase error smaller than 3.5 degrees. In order to characterize the magnetic field properties of the superconducting coils local field measurements have been performed by moving a set of Hall probes on a sledge in a liquid helium bath. The results of these investigations are presented.

  5. Status of the development of superconducting undulators at ANKA

    International Nuclear Information System (INIS)

    In order to produce high-brilliance hard X-ray photon beams, permanent magnet short-period undulators are applied in many synchrotron facilities worldwide. Superconducting undulators (SCUs) have the potential to further increase the spectral range and brilliance. At the ANKA (ÅNgstrom source KArlsruhe) synchrotron radiation facility, we thus pursue an SCU-focused research and development program in a collaboration between the Karlsruhe Institute of Technology (KIT) and Babcock Noell GmbH (BNG), the status of which is reported in this contribution. The effort to develop instruments and tools for quality assessment of the magnetic field of SCUs and to enhance the understanding of beam heat load mechanisms in a cold bore is also described.

  6. Training and magnetic field measurements of the ANKA superconducting undulator

    Energy Technology Data Exchange (ETDEWEB)

    Saez de Jauregui, David; Baumbach, Tilo; Casalbuoni, Sara; Gerstl, Stefan; Hagelstein, Michael [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Boffo, Cristian; Walter, Wolfgang [Babcock Noell GmbH, Wuerzburg (Germany)

    2011-07-01

    In 2011 a 1.5 m long superconducting undulator with a period length of 15mm is scheduled to be installed in ANKA. This insertion device is planned to be the light source of the new beamline NANO for high resolution X-ray diffraction. The key specifications of the system are an undulator parameter K higher than 2 (for a magnetic gap of 5mm) and a phase error smaller than 3.5 degrees. In order to characterize the magnetic field properties of the superconducting coils local field measurements have been performed by moving a set of Hall probes on a sledge in a liquid helium bath. The results of these investigations are presented.

  7. Rapid and sensitive XAFS using tunable X-ray undulator

    International Nuclear Information System (INIS)

    Novel experimental techniques for rapid and sensitive X-ray absorption fine structure (XAFS) using a tunable X-ray undulator are described. It is shown that a wide energy range (5-25 keV) can be covered by varying the deflection parameter K using the first and third order radiation. Optimizing the band width of undulator by controling the tapered magnet arrays, the rapid measurement of extended X-ray absorption fine structure (EXAFS) in a fluorescence mode is feasible by quick scanning of either a double-crystal monochromator or a mask across the polychromatic beam in an energy-dispersive geometry. Feasibility for both cases is examined and arrangements of optical components are described. (author)

  8. The U5.0 Undulator for the ALS

    International Nuclear Information System (INIS)

    The U5.0 Undulator, an 89 period, 5 cm period length, 4.6 m long insertion device has been designed and is in fabrication. This undulator will be the first high brightness source, in the 50 to 1500 eV range, for the Advanced Light Source (ALS) and is scheduled for completion in 1992. A modular hybrid configuration utilizing Nd-Fe-B permanent magnet material and vanadium permendur is used that achieves 0.837 Tesla effective peak field. Correction of the vertical field integral is with permanent magnet rotors at the ends. Gap adjustment is with an arrangement of roller screws, chains drives, a gear reduction unit and a stepper motor driven by a closed loop control system. The vacuum chamber design is a two-piece, machined and welded 5083-H321 aluminum construction of 5.1 m length. Magnetic design, subsystem design and fabrication progress are presented. 12 refs., 4 figs., 2 tabs

  9. Crystal Undulator As A Novel Compact Source Of Radiation

    CERN Document Server

    Bellucci, S; Biryukov, V M; Britvich, G I; Chesnokov, Yu A; Giannini, G; Guidi, V; Ivanov, Y M; Kotov, V I; Maisheev, V A; Malagu, C; Martinelli, G; Petrunin, A A; Pikalov, V A; Skorobogatov, V V; Stefancich, M; Tombolini, F; Vincenzi, D; Chesnokov, Yu. A.; Ivanov, Yu. M.

    2004-01-01

    A crystalline undulator (CU) with periodically deformed crystallographic planes is capable of deflecting charged particles with the same strength as an equivalent magnetic field of 1000 T and could provide quite a short period L in the sub-millimeter range. We present an idea for creation of a CU and report its first realization. One face of a silicon crystal was given periodic micro-scratches (grooves), with a period of 1 mm, by means of a diamond blade. The X-ray tests of the crystal deformation have shown that a sinusoidal-like shape of crystalline planes goes through the bulk of the crystal. This opens up the possibility for experiments with high-energy particles channeled in CU, a novel compact source of radiation. The first experiment on photon emission in CU has been started at LNF with 800 MeV positrons aiming to produce 50 keV undulator photons.

  10. Subradiant spontaneous undulator emission through collective suppression of shot noise

    Science.gov (United States)

    Ratner, D.; Hemsing, E.; Gover, A.; Marinelli, A.; Nause, A.

    2015-05-01

    The phenomenon of Dicke's subradiance, in which the collective properties of a system suppress radiation, has received broad interest in atomic physics. Recent theoretical papers in the field of relativistic electron beams have proposed schemes to achieve subradiance through suppression of shot noise current fluctuations. The resulting "quiet" beam generates less spontaneous radiation than emitted even by a shot noise beam when oscillating in an undulator. Quiet beams could have diverse accelerator applications, including lowering power requirements for seeded free-electron lasers and improving efficiency of hadron cooling. In this paper we present experimental observation of a strong reduction in undulator radiation, demonstrating the feasibility of noise suppression as a practical tool in accelerator physics.

  11. The U5.0 undulator for the ALS

    International Nuclear Information System (INIS)

    The U5.0 Undulator, an 89 period, 5 cm period length, 4.6 m long insertion device has been designed and is in fabrication. This undulator will be the first high brightness source, in the 50 to 1500 eV range, for the Advanced Light Source (ALS) and is scheduled for completion in 1992. A modulator hybrid configuration utilizing Nd-Fe-B permanent magnet and vanadium permendur is used that achieves 0.837 Tesla effective peak field. Correction of the vertical field integral is with permanent magnet rotors at the ends. Gap adjustment is with an arrangement of roller screws, chain drives, a gear reduction unit and a stepper motor driven by a closed loop control system. The vacuum chamber design is a two-piece, machined and welded 5083-H321 aluminum construction of 5.1 m length. Magnetic design, subsystem design and fabrication progress are presented

  12. Construction of CHESS compact undulator magnets at Kyma

    Science.gov (United States)

    Temnykh, Alexander B.; Lyndaker, Aaron; Kokole, Mirko; Milharcic, Tadej; Pockar, Jure; Geometrante, Raffaella

    2015-05-01

    In 2014 KYMA S.r.l. has built two CHESS Compact Undulator (CCU) magnets that are at present installed and successfully operate at the Cornell Electron Storage Ring. This type of undulator was developed for upgrade of Cornell High Energy Synchrotron Source beam-lines, but it can be used elsewhere as well. CCU magnets are compact, lightweight, cost efficient and in-vacuum compatible. They are linearly polarized undulators and have a fixed gap. Magnetic field tuning is achieved by phasing (shifting) top magnetic array relative bottom. Two CCUs constructed by KYMA S.r.l. have 28.4 mm period, 6.5 mm gap, 0.93 T peak field. Magnetic structure is of PPM type, made with NdFeB (40UH grade) permanent magnet material. Transitioning from the laboratory to industrial environment for a novel design required additional evaluation, design adjusting and extensive testing. Particular attention was given to the soldering technique used for fastening of the magnetic blocks to holders. This technique had thus far never been used before for undulator magnet construction by industry. The evaluation included tests of different types of soldering paste, measurements of strength of solder and determining the deformations of the soldered magnet and holder under simulated loading forces. This paper focuses on critical features of the CCU design, results of the soldering technique testing and the data regarding permanent magnets magnetization change due to soldering. In addition it deals with optimization-assisted assembly and the performance of the assembled devices and assesses some of the results of the CCU magnets operation at CESR.

  13. Design, construction, and characterization of an electromagnetic small period undulator

    International Nuclear Information System (INIS)

    In this work a new concept for the construction of small period electromagnetic insertion devices is presented. The construction of a pulsed undulator with 2 mm gap and 8 mm magnetic period is described, as well as its pulser. The magnetic measurement system is presented and the obtained data is compared with the calculated field. Finally, the possible application of this device for synchrotron radiation production in LINAC's and a future cw superconducting version for storage rings is discussed

  14. Elliptically polarizing undulator beamlines at the Advanced Light Source

    International Nuclear Information System (INIS)

    Circular polarization insertion devices and beamlines at the Advanced Light Source are described. The facility will consist of multiple undulators feeding two independent beamlines, one optimized for microscopy and the other for spectroscopy. The energy range of the beamlines will go from below 100 eV to 1,800 eV, enabling studies of the magnetically important L2,3 edges of transition metals and the M4,5 edges of rare earths

  15. Elliptically polarizing undulator beamlines at the Advanced Light Source

    International Nuclear Information System (INIS)

    Circular polarization insertion devices and beamlines at the Advanced Light Source are described. The facility will consist of multiple undulators feeding two independent beamlines, one optimized for microscopy and the other for spectroscopy. The energy range of the beamlines will go from below 100 eV to 1800 eV, enabling studies of the magnetically important L2,3 edges of transition metals and the M4,5 edges of rare earths. copyright 1996 American Institute of Physics

  16. Image Charge Undulator: Theoretical Model and Technical Issues

    International Nuclear Information System (INIS)

    A new device, an image charge undulator, has been proposed recently [1] to utilize this mechanism for generating coherent hard radiation. We demonstrate physics principle of this device by a 2D model of a uniform sheet beam. The transverse image charge wakefields, synchrotron radiation FR-equency and coherent radiation gain length are presented. We discuss a proof-of-principle experiment that takes into consideration such technical issues as grating fabrication, flat beams and beam alignment

  17. Crossed undulator system for a variable polarization synchrotron radiation source

    International Nuclear Information System (INIS)

    A crossed undulator system can produce synchrotron radiation whose polarization is arbitrary and adjustable. The polarization can be linear and modulated between two mutually perpendicular directions, or it can be circular and can be modulated between right and left circular polarizations. The system works on low emittance electron storage rings and can cover a wide spectral range. Topics discussed include the basic principle of the system, the design equations and the limitations in performance

  18. Gap-tapered undulators for high-photon-energy synchrotron radiation production

    International Nuclear Information System (INIS)

    Narrow-gap, short-period undulators are of interest to maximize the achievable photon energy at lower-energy storage rings. An important consideration is matching the e-beam beta function in the straight section to the vertical aperture at the insertion device so as to maximize vertical acceptance, beam lifetime, and injection efficiency. Various approaches have been considered such as in-vacuum undulators, undulators with flexible vacuum chambers, and superconducting undulators. In each of these the undulator gap is constant along the undulator length, in which case the optimum beta function is equal to one-half the length. We discuss an alternate approach in which the undulator gap is tapered to follow the transverse profile of the e-beam envelope. This allows the use of a relatively long undulator within a low-beta straight section. The undulator gap is physically and magnetically matched to the e-beam envelope throughout the straight section. The undulator period is varied to maintain constant photon resonance while everywhere maximizing the magnetic field strength. This approach optimizes the high-photon-energy synchrotron radiation generation. The achievable synchrotron radiation spectral properties and tunability of such a device are examined

  19. Fiber-optic link for the RF phase reference distribution system for the XFEL and TESLA projects

    Science.gov (United States)

    Czuba, Krzysztof; Eints, Frank; Felber, Matthias; Simrock, Stefan

    2005-02-01

    The UV Free-Electron Laser (UVFEL) and The TeV-Energy Superconducting Linear Accelerator (TESLA) projects will require phase synchronization of 0.1 ps short term (millisecond), 1 ps short term (minutes) and 10 ps long term (days). The stringent synchronization requirement of 10fs was given for the X-Ray Free- Electron Laser (XFEL). To fufill this requirement the XFEL may use a fiber laser as reference generator. But this requirement applies for a special location only, therefore the RF phase reference distribution system developed UVFEL and TESLA will also be used in the XFEL. The RF phase reference distribution system must deliver phase stable signals to hundreds of stations over a length of 33 km. Long, optical fiber based links are planned to be an important part of the entire distribution system. This paper describes the concept of a long optical link, with a feedback system suppressing long term drifts of the RF signal phase. Stability requirements are given and most important design issues affecting system performance are discussed. Finally, an experimental setup and measurement results demonstrating system performance is shown.

  20. Atomistic Simulations of High-intensity XFEL Pulses on Diffractive Imaging of Nano-sized System Dynamics

    Science.gov (United States)

    Ho, Phay; Knight, Christopher; Bostedt, Christoph; Young, Linda; Tegze, Miklos; Faigel, Gyula

    2016-05-01

    We have developed a large-scale atomistic computational method based on a combined Monte Carlo and Molecular Dynamics (MC/MD) method to simulate XFEL-induced radiation damage dynamics of complex materials. The MD algorithm is used to propagate the trajectories of electrons, ions and atoms forward in time and the quantum nature of interactions with an XFEL pulse is accounted for by a MC method to calculate probabilities of electronic transitions. Our code has good scalability with MPI/OpenMP parallelization, and it has been run on Mira, a petascale system at the Argonne Leardership Computing Facility, with particle number >50 million. Using this code, we have examined the impact of high-intensity 8-keV XFEL pulses on the x-ray diffraction patterns of argon clusters. The obtained patterns show strong pulse parameter dependence, providing evidence of significant lattice rearrangement and diffuse scattering. Real-space electronic reconstruction was performed using phase retrieval methods. We found that the structure of the argon cluster can be recovered with atomic resolution even in the presence of considerable radiation damage. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division.

  1. Antiaging activity of low molecular weight peptide from Paphia undulate

    Institute of Scientific and Technical Information of China (English)

    CHEN Xin; CAI Bingna; CHEN Hua; PAN Jianyu; CHEN Deke; SUN Huili

    2013-01-01

    Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats,aged Kunming mice,ultraviolet-exposed rats,and thermally injured rats was investigated.P.undulate flesh was homogenized and digested using papain under optimal conditions,then subjected to Sephadex G-25 chromatography to isolate the LMWP.Administration of LMWP significantly reversed D-galactose-induced oxidative stress by increasing the activities ofglutathione peroxidase (GPx) and catalase (CAT),and by decreasing the level ofmalondialdehyde (MDA).This process was accompanied by increased collagen synthesis.The LMWP prevented photoaging and promoted dermis recovery and remission of elastic fiber hyperplasia.Furthermore,treatment with the LMWP helped to regenerate elastic fibers and the collagen network,increased superoxide dismutase (SOD)in the serum and significantly decreased MDA.Thermal scald-induced inflammation and edema were also relieved by the LWMP,while wound healing in skin was promoted.These results suggest that the LMWP from P.undulate could serve as a new antiaging substance in cosmetics.

  2. Antiaging activity of low molecular weight peptide from Paphia undulate

    Science.gov (United States)

    Chen, Xin; Cai, Bingna; Chen, Hua; Pan, Jianyu; Chen, Deke; Sun, Huili

    2013-05-01

    Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats, aged Kunming mice, ultraviolet-exposed rats, and thermally injured rats was investigated. P. undulate flesh was homogenized and digested using papain under optimal conditions, then subjected to Sephadex G-25 chromatography to isolate the LMWP. Administration of LMWP significantly reversed D-galactose-induced oxidative stress by increasing the activities of glutathione peroxidase (GPx) and catalase (CAT), and by decreasing the level of malondialdehyde (MDA). This process was accompanied by increased collagen synthesis. The LMWP prevented photoaging and promoted dermis recovery and remission of elastic fiber hyperplasia. Furthermore, treatment with the LMWP helped to regenerate elastic fibers and the collagen network, increased superoxide dismutase (SOD) in the serum and significantly decreased MDA. Thermal scald-induced inflammation and edema were also relieved by the LWMP, while wound healing in skin was promoted. These results suggest that the LMWP from P. undulate could serve as a new antiaging substance in cosmetics.

  3. Wave scattering by a permeable barrier over undulating bed topography

    Science.gov (United States)

    Choudhary, A.; Martha, S. C.

    2016-06-01

    The scattering of surface water waves by bottom undulation in the presence of a permeable vertical barrier is investigated for its solution. A mixed boundary value problem (BVP) arises here in a natural way while examining this physical problem. Regular perturbation analysis is employed to determine the solution of the BVP. By utilizing this analysis the given BVP reduces to two different BVPs up to first order. The solution of the zeroth order BVP is obtained with the aid of eigenfunction expansion method in conjunction with least-squares approximation. The first order BVP is solved with the help of the Green's integral theorem and the physical quantities, namely the reflection and transmission coefficients, are obtained in the form of integrals which involve the bottom undulation and the solution of the zeroth order BVP. A particular form of the bottom undulation which closely resembles to some obstacles made by nature due to sedimentation and ripple growth of sand, is considered to evaluate these integrals. The variation of these coefficients is examined for different values of the porous effect parameter, barrier length, number of ripples and ripple amplitude.

  4. Different charges in the same bunch train at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Kot, Yauhen; Limberg, Torsten; Zagorodnov, Igor

    2013-11-15

    The injector of the European XFEL was initially designed for the operation with 1nC bunch charges. Later the flexibility of the nominal design of the injector with respect to the bunch charge was studied and extended also for smaller bunch charges down to 20 pC. A very tempting upgrade of this extension would be the operation of the European XFEL with different charges in the same train. It would make it suitable also for the experiments which require simultaneously different SASE pulse length or radiation power. Operation of two bunches within the same train sets new requirements on the working points of the injector which are to be satisfied additionally to the ones of a single charge operation. From the beam dynamics point of view here is to mention the similarity of the beam optical functions after the first accelerating module and suitable for lasing shapes of both bunches in the train at the end of the linac. Due to different charges and thus to different space charge forces which act on bunches during the passage of the linac the last condition cannot be easily satisfied even if the similarity of optical functions at the beginning of the linac is achieved. A more subtle analysis of the interplay between mismatch of beam optical functions, emittance growth in the injector and different 6D beam dynamics in the linac is needed with the final goal of successful lasing of both charges. In this paper we have investigated the possibility of the operation of different charges in the bunch train for the nominal design of the injector and for the case that it is extended by an additional laser system on the cathode. We have examined the problem of similarity of beam optical functions for different bunches in a train. We report also about the sensitivity of the beam optical functions on the chosen compression scenario and give an overview over the working points for the settings at the injector for single charge operation as well as combined working points for

  5. Different charges in the same bunch train at the European XFEL

    International Nuclear Information System (INIS)

    The injector of the European XFEL was initially designed for the operation with 1nC bunch charges. Later the flexibility of the nominal design of the injector with respect to the bunch charge was studied and extended also for smaller bunch charges down to 20 pC. A very tempting upgrade of this extension would be the operation of the European XFEL with different charges in the same train. It would make it suitable also for the experiments which require simultaneously different SASE pulse length or radiation power. Operation of two bunches within the same train sets new requirements on the working points of the injector which are to be satisfied additionally to the ones of a single charge operation. From the beam dynamics point of view here is to mention the similarity of the beam optical functions after the first accelerating module and suitable for lasing shapes of both bunches in the train at the end of the linac. Due to different charges and thus to different space charge forces which act on bunches during the passage of the linac the last condition cannot be easily satisfied even if the similarity of optical functions at the beginning of the linac is achieved. A more subtle analysis of the interplay between mismatch of beam optical functions, emittance growth in the injector and different 6D beam dynamics in the linac is needed with the final goal of successful lasing of both charges. In this paper we have investigated the possibility of the operation of different charges in the bunch train for the nominal design of the injector and for the case that it is extended by an additional laser system on the cathode. We have examined the problem of similarity of beam optical functions for different bunches in a train. We report also about the sensitivity of the beam optical functions on the chosen compression scenario and give an overview over the working points for the settings at the injector for single charge operation as well as combined working points for

  6. Computational and experimental study on dynamic behavior of underwater robots propelled by bionic undulating fins

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Bionic undulating fins, inspired by undulations of the median and/or paired fin (MPF) fish, have a bright prospective for un-derwater missions with higher maneuverability, lower noisy, and higher efficiency. In the present study, a coupled computa-tional fluid dynamics (CFD) model was proposed and implemented to facilitate numerical simulations on hydrodynamic ef-fects of the bionic undulating robots. Hydrodynamic behaviors of underwater robots propelled by two bionic undulating fins were computationally and experimentally studied within the three typical desired movement patterns, i.e., marching, yawing and yawing-while-marching. Moreover, several specific phenomena in the bionic undulation mode were unveiled and dis-cussed by comparison between the CFD and experimental results under the same kinematics parameter sets. The contributed work on the dynamic behavior of the undulating robots is of importance for study on the propulsion mechanism and control algorithms.

  7. Numerical investigation of the radiation characteristics of a variable-period helical undulator

    International Nuclear Information System (INIS)

    A helical undulator with a variable-period capability has been developed at the Korea Atomic Energy Research Institute (KAERI) to generate high power radiation in the terahertz range. A simulation code for the spontaneous emission from an electron beam inside an undulator has been developed to characterize the performance of the undulator. In the case of the KAERI undulator, there is a non-negligible high-order harmonics in the longitudinal field distribution compared with a bifilar one.The axial velocity modulation by the high-order harmonics in the field distribution has been found to lead to small deviation of the spectrum of spontaneous emission from the KAERI undulator with respect to the bifilars one. The gain functions obtained from the spontaneous emission spectra according to the Madey theory, show similar shapes for both undulators

  8. An Overview of the MaRIE X-FEL and Electron Radiography LINAC RF Systems

    International Nuclear Information System (INIS)

    The purpose of the Matter-Radiation Interactions in Extremes (MaRIE) facility at Los Alamos National Laboratory is to investigate the performance limits of materials in extreme environments. The MaRIE facility will utilize a 12 GeV linac to drive an X-ray Free-Electron Laser (FEL). Most of the same linac will also be used to perform electron radiography. The main linac is driven by two shorter linacs; one short linac optimized for X-FEL pulses and one for electron radiography. The RF systems have historically been the one of the largest single component costs of a linac. We will describe the details of the different types of RF systems required by each part of the linacs. Starting with the High Power RF system, we will present our methodology for the choice of RF system peak power and pulselength with respect to klystron parameters, modulator parameters, performance requirements and relative costs. We will also present an overview of the Low Level RF systems that are proposed for MaRIE and briefly describe their use with some proposed control schemes.

  9. An Overview of the MaRIE X-FEL and Electron Radiography LINAC RF Systems

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Joseph Thomas III [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rees, Daniel Earl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scheinker, Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sheffield, Richard L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-04

    The purpose of the Matter-Radiation Interactions in Extremes (MaRIE) facility at Los Alamos National Laboratory is to investigate the performance limits of materials in extreme environments. The MaRIE facility will utilize a 12 GeV linac to drive an X-ray Free-Electron Laser (FEL). Most of the same linac will also be used to perform electron radiography. The main linac is driven by two shorter linacs; one short linac optimized for X-FEL pulses and one for electron radiography. The RF systems have historically been the one of the largest single component costs of a linac. We will describe the details of the different types of RF systems required by each part of the linacs. Starting with the High Power RF system, we will present our methodology for the choice of RF system peak power and pulselength with respect to klystron parameters, modulator parameters, performance requirements and relative costs. We will also present an overview of the Low Level RF systems that are proposed for MaRIE and briefly describe their use with some proposed control schemes.

  10. Commissioning and performance of the beam monitor system for XFEL/SPring-8 'SACLA'

    International Nuclear Information System (INIS)

    The beam monitor system for the XFEL facility 'SACLA' is demanded to measure a beam position with sub-μm resolution, a beam profile with few-μm resolution, a temporal structure with 10 fs resolution. Therefore, we developed and constructed the beam monitor system consisting of rf cavity beam position monitors (RF-BPM), screen monitors (SCM) with OTR targets and YAG:Ce scintillators, high-speed differential current transformers (CT), an rf deflector system (RFDEF), a streak camera and coherent synchrotron radiation (CSR) monitors. After the commissioning of the beam monitor system, the position resolution of the RF-BPM was found to be less than 0.6 μm (RMS) and the temporal resolution of the RFDEF was approximately 10 fs. Although SCMs observed anomalous radiation due to coherent OTR (COTR), COTR was diminished by a YAG:Ce target with an OTR mask. As a result of the beam tuning with the beam monitor system, SACLA succeeded the lasing with a wavelength of 0.12 nm. (author)

  11. High-speed differential current-transformer monitor for SACLA of XFEL/SPring-8

    International Nuclear Information System (INIS)

    The XFEL, which was named SACLA, was constructed in the SPring-8 site. In the SACLA, the bunch length of an electron beam is compressed from 1 ns to 30 fs, and the beam charge is decreased from 1 nC to 0.3 nC for lasing. A new current-transformer (CT) monitor was developed for the two purposes: one is to measure the charge of the electron beam and the other is to obtain the bunch length in velocity bunching process. The CT monitor has differential outputs and generates high-speed signals. The differential output-signal suppresses common-mode noise from the klystron modulator by a factor of ten. The CT has a sensitivity of 1 pC and a dynamic range of 1 nC. High-speed output-signal, which has the shortest rise-time of 200 ps and the shortest pulse width of 400 ps, is able to measure the bunch length and the time-of-flight at the injector part of the SACLA. Thus, the new CT performance was confirmed to be sufficient for the SACLA. (author)

  12. Using the X-FEL to understand X-ray Thomson scattering for partially ionized plasmas

    CERN Document Server

    Nilsen, J; Cheng, K T

    2012-01-01

    For the last decade numerous researchers have been trying to develop experimental techniques to use X-ray Thomson scattering as a method to measure the temperature, electron density, and ionization state of high energy density plasmas such as those used in inertial confinement fusion. With the advent of the X-ray free electron laser (X-FEL) at the SLAC Linac Coherent Light Source (LCLS) we now have such a source available in the keV regime. One challenge with X-ray Thomson scattering experiments is understanding how to model the scattering for partially ionized plasmas. Most Thomson scattering codes used to model experimental data greatly simplify or neglect the contributions of the bound electrons to the scattered intensity. In this work we take the existing models of Thomson scattering that include elastic ion-ion scattering and the electron-electron plasmon scattering and add the contribution of the bound electrons in the partially ionized plasmas. Except for hydrogen plasmas almost every plasma that is st...

  13. Electron correlation in two-photon double ionization of helium from attosecond to XFEL pulses

    International Nuclear Information System (INIS)

    We investigate the role of electron correlation in the two-photon double ionization of helium for ultrashort pulses in the extreme ultraviolet (XUV) regime with durations ranging from a hundred attoseconds to a few femtoseconds. We perform time-dependent ab initio calculations for pulses with mean frequencies in the so-called 'sequential' regime (ℎω > 54.4 eV). Electron correlation induced by the time correlation between emission events manifests itself in the angular distribution of the ejected electrons, which strongly depends on the energy sharing between them. We show that for ultrashort pulses two-photon double ionization probabilities scale non-uniformly with pulse duration depending on the energy sharing between the electrons. Most interestingly we find evidence for an interference between direct ('nonsequential') and indirect ('sequential') double photoionization with intermediate shake-up states, the strength of which is controlled by the pulse duration. This observation may provide a route towards measuring the pulse duration of x-ray free-electron laser (XFEL) pulses.

  14. Regional and Local Geoid Undulations for Computing Orthometric Heights from GPS Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal explains procedures of using regional and local geoid undulations to improve and convert the global positioning system (GPS) elevations (ellipsoidal...

  15. Improvements of the undulator spectral performance by compensating the backing beam deflection

    International Nuclear Information System (INIS)

    This study thoroughly examines how the backing beam deflection affects the undulator spectral performance. Reduction of the undulator spectral intensity owing to backing beam deflection is analytically evaluated based on plane-wave approximation. The results reveal that the amplitude and the slope of the backing beam deflection affect the undulator spectral performance. Provided is a novel figure-of-merit, rms of the regressed accumulated gap deviation, to determine the backing beam deflection budget. An example of a 3.9 m undulator supporting carriage mounted with 50-mm period length undulator magnet (U5) under a maximum magnetic loading of 5 metric tons at a minimum operating gap of 14 mm, is provided. Its mechanical features are first examined via 3D commercial finite element code ANSYS that concludes the backing beam deflection is influenced heavily by the rigidity of the undulator support frames. Examining the corresponding spectral performance shows that significantly diminishing the undulator spectral degradation by backing beam deflection is attainable by compensating the deflection at the undulator minimum operating gap properly. The numerical results agree well with those deduced from the measured magnetic field of the as-built undulator

  16. In vacuum figure-8 undulator for hard X-rays with both horizontal and vertical polarization

    International Nuclear Information System (INIS)

    A figure-8 undulator of the in-vacuum type has been adopted as an insertion device for BL24XU, the Hyogo Beamline at SPring-8, to provide hard X-rays with both horizontal and vertical polarization instead of a tandem undulator consisting of horizontal and vertical undulators. The undulator will be operated with the gap almost fixed at 11.6 mm to provide the fundamental radiation with horizontal polarization at 9.5 keV and the 1.5th harmonic with vertical polarization at 14 keV

  17. Laser-driven soft-X-ray undulator source

    International Nuclear Information System (INIS)

    The experimental results described in this thesis demonstrate the successful synergy between the research fields described above: the development of an undulator source driven by laser-plasma accelerated electron beams. First efforts in this new field have led to the production of radiation in the visible to infrared part of the electromagnetic spectrum [Schlenvoigt et al., 2008]. In contrast to these early achievements, the experiment described here shows the successful production of laser-driven undulator radiation in the soft-X-ray range with a remarkable reproducibility. The source produced tunable, collimated beams with a wavelength of ∝17 nm from a compact setup. Undulator spectra were detected in ∝70% of consecutive driver-laser shots, which is a remarkable reproducibility for a first proof-of-concept demonstration using ultra-high intensity laser systems. This can be attributed to a stable electron acceleration scheme as well as to the first application of miniature magnetic quadrupole lenses with laseraccelerated beams. The lenses significantly reduce the electron beam divergence and its angular shot-to-shot fluctuations The setup of this experiment is the foundation of potential university-laboratory-sized, highly-brilliant hard X-ray sources. By increasing the electron energy to about 1 GeV, X-ray pulses with an expected duration of ∝10 fs and a photon energy of 1 keV could be produced in an almost identical arrangement. It can also be used as a testbed for the development of a free-electron laser of significantly smaller dimension than facilities based on conventional accelerators [Gruener et al., 2007]. Such compact sources have the potential for application in many fields of science. In addition, these developments could lead to ideal sources for ultrafast pump-probe experiments due to the perfect synchronization of the X-ray beam to the driver laser. (orig.)

  18. Laser-driven soft-X-ray undulator source

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Matthias

    2010-08-04

    The experimental results described in this thesis demonstrate the successful synergy between the research fields described above: the development of an undulator source driven by laser-plasma accelerated electron beams. First efforts in this new field have led to the production of radiation in the visible to infrared part of the electromagnetic spectrum [Schlenvoigt et al., 2008]. In contrast to these early achievements, the experiment described here shows the successful production of laser-driven undulator radiation in the soft-X-ray range with a remarkable reproducibility. The source produced tunable, collimated beams with a wavelength of {proportional_to}17 nm from a compact setup. Undulator spectra were detected in {proportional_to}70% of consecutive driver-laser shots, which is a remarkable reproducibility for a first proof-of-concept demonstration using ultra-high intensity laser systems. This can be attributed to a stable electron acceleration scheme as well as to the first application of miniature magnetic quadrupole lenses with laseraccelerated beams. The lenses significantly reduce the electron beam divergence and its angular shot-to-shot fluctuations The setup of this experiment is the foundation of potential university-laboratory-sized, highly-brilliant hard X-ray sources. By increasing the electron energy to about 1 GeV, X-ray pulses with an expected duration of {proportional_to}10 fs and a photon energy of 1 keV could be produced in an almost identical arrangement. It can also be used as a testbed for the development of a free-electron laser of significantly smaller dimension than facilities based on conventional accelerators [Gruener et al., 2007]. Such compact sources have the potential for application in many fields of science. In addition, these developments could lead to ideal sources for ultrafast pump-probe experiments due to the perfect synchronization of the X-ray beam to the driver laser. (orig.)

  19. The U5.0 Undulator for the ALS

    International Nuclear Information System (INIS)

    the U5.0 Undulator, and 89 period, 5 cm period length, 4.6 m long insertion device has been designed, is being fabricated and is scheduled for completion in early 1992. This undulator will be the first high brightness source, in the 50 to 1500 eV range, for the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory. A hybrid magnetic configuration using Nd-Fe-B permanent magnet material and vanadium permendur poles has been selected to achieve the field quality needed to meet performance requirements. The magnetic structure is modular with each half consisting of 5 assembly sections, which provide the periodic structure, and end structures, for entrance and exit correction, mounted on a steel backing beam. Each assembly section consists of 35 half-period pole assemblies bolted to a mount. The required 0.837 Tesla effective peak field at a 1.4 cm gap has been verified with model measurements. Vertical field integral correction is accomplished with the end structures, each having an arrangement of permanent magnet rotors which will be adjusted to minimize electron beam missteering over the undulator operating field range. To reduce the effect of environmental fields, the steel backing beams are connected through parallel, low-reluctance, Ni-Fe hinges. The magnetic structure is connected through four roller-nuts to the drive system that provides gap adjustment with an arrangement of roller screws, chain drives, a gear reduction unit and a stepper motor driven by a closed loop control system. Magnetic structure and drive system support are from a 2.4 m high structure which includes a support base with four vertical supports. The vacuum chamber design is a two-piece machined and welded 5083-H321 aluminum construction of 5.1 m length. Pumping is with a combination of ion, TSP and NEG pumps. Magnetic design, subsystem design and fabrication progress are presented

  20. Rationing with baselines

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moreno-Ternero, Juan D.; Østerdal, Lars Peter Raahave

    2013-01-01

    We introduce a new operator for general rationing problems in which, besides conflicting claims, individual baselines play an important role in the rationing process. The operator builds onto ideas of composition, which are not only frequent in rationing, but also in related problems such as...... bargaining, choice, and queuing. We characterize the operator and show how it preserves some standard axioms in the literature on rationing. We also relate it to recent contributions in such literature....

  1. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

    Energy Technology Data Exchange (ETDEWEB)

    Wootton, Kent

    2015-09-17

    In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 ± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

  2. Phase space distribution of brilliance of undulator sources

    International Nuclear Information System (INIS)

    As an optical source, an undulator can be described by its distribution of brilliance in phase space (angle and position in the transverse plane). This is a convolution of single-particle diffraction pattern and electron beam distribution. Approximate peak brilliance and phase space widths are given. By analogy between brilliance and Wigner function, the depth-of-field and diffraction widths are shown to be essentially the same thing. The peak brilliance is shown to have a broad maximum as a function of the beam β function (β ≅ L/2π) but is practically independent of β at short wavelengths

  3. Development of a Quasi-Periodic Undulator for the HLS

    CERN Document Server

    Yang, Yufeng; Chen, Wan; Jia, Qika; Sun, Shuchen; Li, Zhiqiang

    2014-01-01

    China's first quasi-periodic undulator (QPU) has been developed for the Hefei Light Source (HLS). It uses a magnetic configuration with varied thicknesses of NdFeB blocks, based on the QPU of European Synchrotron Radiation Facility (ESRF). Depression of 3rd harmonic radiation is significantly improved over the ESRF QPU, as deduced from the measured magnetic fields. A method of configuring shims of different geometries and sizes, based on a symmetric principle to correct multi-pole field integrals, was demonstrated.

  4. The TDAQ Baseline Architecture

    CERN Multimedia

    Wickens, F J

    The Trigger-DAQ community is currently busy preparing material for the DAQ, HLT and DCS TDR. Over the last few weeks a very important step has been a series of meetings to complete agreement on the baseline architecture. An overview of the architecture indicating some of the main parameters is shown in figure 1. As reported at the ATLAS Plenary during the February ATLAS week, the main area where the baseline had not yet been agreed was around the Read-Out System (ROS) and details in the DataFlow. The agreed architecture has: Read-Out Links (ROLs) from the RODs using S-Link; Read-Out Buffers (ROB) sited near the RODs, mounted in a chassis - today assumed to be a PC, using PCI bus at least for configuration, control and monitoring. The baseline assumes data aggregation, in the ROB and/or at the output (which could either be over a bus or in the network). Optimization of the data aggregation will be made in the coming months, but the current model has each ROB card receiving input from 4 ROLs, and 3 such c...

  5. Displace measurement of building floor and alignment by wire positioning system (WPS) at XFEL

    International Nuclear Information System (INIS)

    The floor of undulator tunnel shifts maximum 50 μm in the north-south direction between the 110m east-west stretched wire. This change time seems seasonally but one month faster than that of the under-floor temperature. The linearity of Kevlar carbon wires were tested by stretching two ones for 41m which distances were same in the parallel direction. The distance between these wires were measured by Fogale two WPS's every 5 meter. The distances between two wires were about 175mm and fluctuated within 10μm. The monuments positions measured by WPS's agreed with that by the laser tracker T3 of API within 50μm through the 130m length. (author)

  6. Undulating fins produce off-axis thrust and flow structures.

    Science.gov (United States)

    Neveln, Izaak D; Bale, Rahul; Bhalla, Amneet Pal Singh; Curet, Oscar M; Patankar, Neelesh A; MacIver, Malcolm A

    2014-01-15

    While wake structures of many forms of swimming and flying are well characterized, the wake generated by a freely swimming undulating fin has not yet been analyzed. These elongated fins allow fish to achieve enhanced agility exemplified by the forward, backward and vertical swimming capabilities of knifefish, and also have potential applications in the design of more maneuverable underwater vehicles. We present the flow structure of an undulating robotic fin model using particle image velocimetry to measure fluid velocity fields in the wake. We supplement the experimental robotic work with high-fidelity computational fluid dynamics, simulating the hydrodynamics of both a virtual fish, whose fin kinematics and fin plus body morphology are measured from a freely swimming knifefish, and a virtual rendering of our robot. Our results indicate that a series of linked vortex tubes is shed off the long edge of the fin as the undulatory wave travels lengthwise along the fin. A jet at an oblique angle to the fin is associated with the successive vortex tubes, propelling the fish forward. The vortex structure bears similarity to the linked vortex ring structure trailing the oscillating caudal fin of a carangiform swimmer, though the vortex rings are distorted because of the undulatory kinematics of the elongated fin. PMID:24072799

  7. Fracture mechanics parameters for cracks on a slightly undulating interface

    Science.gov (United States)

    Yang, Lin; Qu, Jianmin

    1993-11-01

    Typical bimaterial interfaces are nonplanar due to surface facets or roughness. Crack-tip stress fields of an interface crack must be influenced by nonplanarity of the interface. Consequently, interface toughness is affected. The crack-tip fields of a finite crack on an elastic/rigid interface with periodic undulation are studied. Particular emphasis is given to the fracture mechanics parameters, such as the stress intensity factors, crack-tip energy release rate, and crack-tip mode mixity. When the amplitude of interface undulation is very small relative to the crack length (which is the case for rough interfaces), asymptotic analysis is used to convert the nonplanarity effects into distributed dislocations located on the planar interface. Then, the resulting stress fields near the crack tip are obtained by using the Fourier integral transform method. It is found that the stress fields at the crack tip are strongly influenced by nonplanarity of the interface. Generally speaking, nonplanarity of the interface tends to shield the crack tip by reducing the crack-tip stress concentration.

  8. Brightness of synchrotron radiation from undulators and bending magnets

    International Nuclear Information System (INIS)

    We consider the maximum of the Wigner distribution (WD) of synchrotron radiation (SR) fields as a possible definition of SR source brightness. Such figure of merit was originally introduced in the SR community by Kim. The brightness defined in this way is always positive and, in the geometrical optics limit, can be interpreted as maximum density of photon flux in phase space. For undulator and bending magnet radiation from a single electron, the WD function can be explicitly calculated. In the case of an electron beam with a finite emittance the brightness is given by the maximum of the convolution of a single electron WD function and the probability distribution of the electrons in phase space. In the particular case when both electron beam size and electron beam divergence dominate over the diffraction size and the diffraction angle, one can use a geometrical optics approach. However, there are intermediate regimes when only the electron beam size or the electron beam divergence dominate. In this asymptotic cases the geometrical optics approach is still applicable, and the brightness definition used here yields back once more the maximum photon flux density in phase space. In these intermediate regimes we find a significant numerical disagreement between exact calculations and the approximation for undulator brightness currently used in literature. We extend the WD formalism to a satisfactory theory for the brightness of a bending magnet. We find that in the intermediate regimes the usually accepted approximation for bending magnet brightness turns out to be inconsistent even parametrically.

  9. Fuente de Alimentación para los Imanes Superconductores del Acelerador de Partículas Europeo XFEL

    OpenAIRE

    García, O.; Francés, A.; J.M. Fernández; Varela, Pablo; Catalanotto, Giuseppe; Alou Cervera, Pedro; Oliver Ramírez, Jesús Angel; Asensi Orosa, Rafael; Prieto López, Roberto; Uceda Antolín, Javier; Cobos Márquez, José Antonio

    2013-01-01

    En este artículo se presenta la fuente de alimentación que se está diseñando para alimentar los imanes superconductores del acelerador de partículas europeo XFEL que se está construyendo en Hamburgo, cuyas características le hacen el más avanzado del mundo. Un imán superconductor es una carga muy inductiva que debe ser controlada en corriente y que presenta una caída de tensión muy baja cuando está en modo superconductor. La fuente debe ser capaz de alimentar esta carga con una alta fiabilida...

  10. Compact Undulator for the Cornell High Energy Synchrotron Source: Design and Beam Test Results

    International Nuclear Information System (INIS)

    We developed, built and beam tested a novel, compact, in-vacuum undulator magnet based on an adjustable phase (AP) scheme. The undulator is 1 m long with a 5mm gap. It has a pure permanent magnet structure with 24.4mm period and 1.1 Tesla maximum peak field. The device consists of two planar magnet arrays mounted on rails inside of a rectangular box-like frame with 156 mm × 146 mm dimensions. The undulator magnet is enclosed in a 273 mm (10.75) diameter cylindrical vacuum vessel with a driver mechanism placed outside. In May 2012 the CHESS Compact Undulator (CCU) was installed in Cornell Electron Storage Ring and beam tested. During four weeks of dedicated run we evaluated undulator radiation properties as well as magnetic, mechanical and vacuum properties of the undulator magnet. We also studied the effect of the CCU on storage ring beam. The spectral characteristics and intensity of radiation were found to be in very good agreement with expected. The magnet demonstrated reproducibility of undulator parameter K at 1.4 × 10−4 level. It was also found that the undulator K. parameter change does not affect electron beam orbit and betatron tunes.

  11. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator - presentation slides

    Energy Technology Data Exchange (ETDEWEB)

    Wootton, Kent

    2015-09-17

    Direct emittance measurement based on vertical undulator is discussed. Emittance was evaluated from peak ratios, the smallest measured being =0.9 ±0.3 pm rad. The angular distribution of undulator radiation departs from Gaussian approximations, a fact of which diffraction-limited light sources should be aware.

  12. Imaging of an undulator source by phase circular Bragg-Fresnel lenses

    OpenAIRE

    Hartman, Ya.; Tarazona, E; Elleaume, P.; Snigireva, I.; Snigirev, A.

    1994-01-01

    Focusing properties and heatload resistance of a Bragg-Fresnel lens placed in an undulator beam have been demonstrated. The electron beam at an undulator source has been imaged by two setups using Bragg-Fresnel lenses. The first setup is a two-lenses telescope and the second one consists of one circular BFL and an asymmetrically cut crystal.

  13. Imaging of an undulator source by phase circular Bragg-Fresnel lenses

    International Nuclear Information System (INIS)

    Focusing properties and heatload resistance of a Bragg-Fresnel lens placed in an undulator beam have been demonstrated. The electron beam at an undulator source has been imaged by two setups using Bragg-Fresnel lenses. The first setup is a two-lenses telescope and the second one consists of one circular BFL and an asymmetrically cut crystal. (orig.)

  14. Study on the Planar Undulator Scheme with Focusing Properties for PKU-FEL

    CERN Document Server

    Ding, Yuantao; Huang, Senlin; Wang, Yugang; Zhao, Kui; Zhuang, Jiejia

    2004-01-01

    An IR range SASE FEL test facility will be built at Peking University. The project is designed to get the SASE FEL at 7 micron driven by a superconducting accelerator. A hybrid planar Nd-Fe-B undulator is employed and the optimization of the external focus system for the undulator is studied. In the PKU-FEL facility, the electron energy is about 30-40 MeV. The combined function undulator with FODO lattice imposes quite stringent tolerances on the strength of the quads. To solve this problem, the weak natural focusing of the undulator in the vertical plane together with horizontally focusing quads, is proposed to supply the focusing in the facility. The combined function undulator of FOFO lattice and FF lattice in the horizontal plane are studied. Compared with the FODO lattice, the FOFO and FF lattice make the saturation a bit longer and the requirements of the field accuracy for the focusing system are much reduced.

  15. Status of a cylindrical superconducting undulator for the laser wakefield accelerator in Jena

    International Nuclear Information System (INIS)

    Laser-Wakefield accelerators (LWFA) produce electron bunches with several 100 MeV energy within a few millimeters acceleration length, however, with a relatively large energy spread (a few percent). Undulators provide monochromatic radiation with high brilliance. The working principle of undulators requires a small energy spread of the electron beam in the order of 0.1 %. To produce monochromatic undulator radiation with LWF accelerated electrons, a novel iron-free cylindrical superconducting undulator (SCU) is under development at the KIT. This talk gives an overview about the design and the optimisation of the SCU tailored to the particular beam properties of the JETI-LWFA at the University of Jena. In addition a short model test and the construction status of the full scale undulator are shown.

  16. Design and fabrication of PPM and hybrid undulator for free electron laser applications

    International Nuclear Information System (INIS)

    Two undulators for free electron laser applications are under fabrication at Insertion Device Development and Measurement Laboratory, DAVV, Indore. The first one is of PPM type with twenty periods, 50 mm each period. The second one is a hybrid undulator with twenty five periods, 20 mm each period. NdFeB magnets of rectangular cross section 12.5 mm, 12.5 mm and 6.25 mm, 6.25 mm will be used for the undulators respectively. Each magnet length is of 50 mm. Each magnet is scanned by a laser micrometer to ensure gap uniformity along the length of the undulator. In this paper we describe the technical design details of both the undulators.

  17. Photon emission by ultra-relativistic positrons in crystalline undulators: the high-energy regime

    CERN Document Server

    Krause, W; Solov'yov, A V; Greiner, W

    2015-01-01

    This paper discusses the undulator radiation emitted by high-energy positrons during planar channeling in periodically bent crystals. We demonstrate that the construction of the undulator for positrons with energies of 10 GeV and above is only possible if one takes into account the radiative energy losses. The frequency of the undulator radiation depends on the energy of the particle. Thus the decrease of the particle's energy during the passage of the crystal should result in the destruction of the undulator radiation regime. However, we demonstrate that it is possible to avoid the destructive influence of the radiative losses on the frequency of the undulator radiation by the appropriate variation of the shape of the crystal channels. We also discuss a method by which, to our mind, it would be possible to prepare the crystal with the desired properties of its channels.

  18. Status of a cylindrical superconducting undulator for the laser wakefield accelerator in Jena

    Energy Technology Data Exchange (ETDEWEB)

    Afonso Rodriguez, Veronica; Bernhard, Axel; Grau, Andreas; Haerer, Bastian; Peiffer, Peter; Rossmanith, Robert; Weber, Marc; Widmann, Christina [KIT, Karlsruhe (Germany); Kaluza, Malte; Nicolai, Maria; Rinck, Thorsten; Saevert, Alexander [Friedrich Schiller University Jena, Jena (Germany); Jaeckel, Oliver; Reuter, Maria [Helmholtz Institute Jena, Jena (Germany)

    2013-07-01

    Laser-Wakefield accelerators (LWFA) produce electron bunches with several 100 MeV energy within a few millimeters acceleration length, however, with a relatively large energy spread (a few percent). Undulators provide monochromatic radiation with high brilliance. The working principle of undulators requires a small energy spread of the electron beam in the order of 0.1 %. To produce monochromatic undulator radiation with LWF accelerated electrons, a novel iron-free cylindrical superconducting undulator (SCU) is under development at the KIT. This talk gives an overview about the design and the optimisation of the SCU tailored to the particular beam properties of the JETI-LWFA at the University of Jena. In addition a short model test and the construction status of the full scale undulator are shown.

  19. Up-grading a 4.7-cm-period plane electromagnetic undulator

    CERN Document Server

    Bogachenkov, V A; Papadichev, V A

    1999-01-01

    Electromagnetic undulators have a number of advantages over permanent-magnet undulators. They are less expensive to fabricate and their field is easily regulated by changing the current, without requiring a complex and expensive precision system for changing the undulator gap. Their main weaknesses are that they require a large power supply and that the field is limited due to yoke saturation mainly because of large axial stray fluxes, particularly in simple constructions. Modernization of a 4.7-cm-period, 20-period long plane electromagnetic undulator of simple design is described. Samarium-cobalt permanent magnets were used to increase the field and decrease power consumption. They were placed between adjacent rings (with opposite sign of field) and while increasing the working field they decreased saturation of the iron yokes. Small lateral displacements of permanent magnets were used to equalize field amplitudes in half periods of the undulator with 0.1% accuracy. Matched input and output to and from the ...

  20. Exploring the undulating plateau: the future of global oil supply.

    Science.gov (United States)

    Jackson, Peter M; Smith, Leta K

    2014-01-13

    In this paper, we analyse the factors that will influence long-term oil supply and describe the future form of the global oil supply profile as an 'undulating plateau' rather than an irreversible, short-term peak or an ever upward trend of increasing production. The ultimate transition from a world of relatively plentiful and cheap oil to one of tight supply and high cost will be slow and challenging. An understanding of the signposts for the future path of supply and the drivers of that profile will be critical to managing the transition. The ultimate form of the global supply curve may well be dictated by demand evolution rather than a limited resource endowment in the longer term. Several factors will probably control future global oil supply. We believe that the scale of global oil resource will not constitute a physical supply limit for at least the next two or three decades. However, all categories of oil resources are already more expensive to develop than in the past, requiring high oil prices to stimulate supply growth. Lower rates of oil demand growth relative to economic growth, combined with more challenging supply growth, will probably lead to an undulating plateau sometime after 2040, with demand from non-Organization for Economic Cooperation and Development states continuing to dominate. Upstream investment requirements and oil price volatility will increase towards and beyond the undulating production plateau. In this new world, high oil prices will induce demand destruction, fuel substitution and ever increasing energy efficiency. As we discuss below, the fundamental differences between the IHS Cambridge Energy Research Associates' (IHS CERA) view of the future of oil supply and many peak oil supply models are the timing of the onset of a dramatic slowdown in the rate of growth of supply and the existence or otherwise of a production plateau. We do not dispute that supply will plateau and eventually fall; the question is when, how and at what price

  1. Design of planar pick-ups for beam position monitor in the bunch compressor at FLASH and XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Angelovski, Aleksandar; Penirschke, Andreas; Jakoby, Rolf [Institut fuer Mikrowellentechnik und Photonik, TU Darmstadt (Germany); Sydlo, Cezary; Mavric, Uros; Gerth, Christopher [DESY, Hamburg (Germany)

    2013-07-01

    For obtaining ultra short electron bunches at the Free Electron Laser at DESY (FLASH) the beam is compressed in magnetic chicanes. During the compression process the precise knowledge of the energy of the bunches is essential for the longitudinal dynamics control. The measurement of the beam position in the chicane allows for non-destructive measurements of the energy. For that purpose, two stripline pick-ups perpendicular to the beam direction are installed in the chicane at FLASH as a part of the Beam Position Monitor. The recent upgrade in the electronics as well as the increased aperture and length of the beam pipe (for the European XFEL) requires the design of new pick-ups which will fulfill the new demands. Namely, the pick-ups should have maximum signal at 3 GHz with minimum reflections. In this talk, we will present the design of planar transmission line pick-ups for FLASH and XFEL. The planar design of the pick-ups can provide for a proper impedance matching to the subsequent electronics as well as sufficient mechanical stability along the aperture when using alumina substrate. A prototype of the pick-ups was build and installed in a non-hermetic body. The measured S parameters are compared to the simulation.

  2. Interfaces modify the undulation spectrum of bicontinuous microemulsions

    Science.gov (United States)

    Holderer, O.; Lipfert, F.; Frielinghaus, H.; Ohl, M.; Richter, D.

    2015-01-01

    Recently, the structure and dynamics of microemulsions adjacent to a planar hydrophilic wall have been characterized using grazing incidence small angle neutron scattering (GISANS) and grazing incidence neutron spin echo (GINSES) spectroscopy, respectively. It has been found that a bicontinuous microemulsion develops a lamellar structure, and that the relaxation rate is faster for a membrane close to the interface compared to the bulk. A model developed by Seifert was employed to explain the discovered acceleration for the near-surface lamellar ordered membranes. In this contribution we present how confinement of a flat interface influences the elastic properties of surfactant membranes and discuss the effect of locally introduced flat interfaces by clay platelets. This analysis sheds light onto the undulation mode spectrum of the surfactant membrane.

  3. Interfaces modify the undulation spectrum of bicontinuous microemulsions

    Directory of Open Access Journals (Sweden)

    Holderer O.

    2015-01-01

    Full Text Available Recently, the structure and dynamics of microemulsions adjacent to a planar hydrophilic wall have been characterized using grazing incidence small angle neutron scattering (GISANS and grazing incidence neutron spin echo (GINSES spectroscopy, respectively. It has been found that a bicontinuous microemulsion develops a lamellar structure, and that the relaxation rate is faster for a membrane close to the interface compared to the bulk. A model developed by Seifert was employed to explain the discovered acceleration for the near-surface lamellar ordered membranes. In this contribution we present how confinement of a flat interface influences the elastic properties of surfactant membranes and discuss the effect of locally introduced flat interfaces by clay platelets. This analysis sheds light onto the undulation mode spectrum of the surfactant membrane.

  4. Undulator field correction by in-situ sorting

    International Nuclear Information System (INIS)

    A novel field-correction method for insertion devices called in-situ sorting has been developed. It is based on a rearrangement of magnet blocks with an analysis of the magnetic data measured for the total device after assembly instead of that for each magnet block before assembly. The field integral at each magnet pole obtained from the magnetic distribution determines how to exchange or flip magnet blocks to reduce both the phase error and multipole components of the field integral. The practical results of the in-situ sorting used for a field correction of an in-vacuum undulator are shown to reveal the validity of the in-situ sorting

  5. Crystalline undulator radiation and sub-harmonic bifurcation of system

    Institute of Scientific and Technical Information of China (English)

    Luo Xiao-Hua; He Wei; Wu Mu-Ying; Shao Ming-Zhu; Luo Shi-Yu

    2013-01-01

    Looking for new light sources,especially short wavelength laser light sources has attracted widespread attention.This paper analytically describes the radiation of a crystalline undulator field by the sine-squared potential.In the classical mechanics and the dipole approximation,the motion equation of a particle is reduced to a generalized pendulum equation with a damping term and a forcing term.The bifurcation behavior of periodic orbits is analyzed by using the Melnikov method and the numerical method,and the stability of the system is discussed.The results show that,in principle,the stability of the system relates to its parameters,and only by adjusting these parameters appropriately can the occurrence of bifurcation be avoided or suppressed.

  6. Analysis of the 3D magnetic field and its errors for undulators with iron poles

    Energy Technology Data Exchange (ETDEWEB)

    Ingold, G.; Bahrdt, J.; Gaupp, A. [BESSY GmbH, Berlin (Germany)] [and others

    1995-12-31

    The attainable field strength and field quality, such as the optical phase error, the electron beam displacement within the undulator and higher order multipoles of the magnetic field, are discussed. These issues are critical to the design and construction of short period undulators for use in short wavelength FEL or for operation in third generation light sources. We discuss two approaches: (i) For superferric undulators the construction of a full length device would rely on the optimum sorting of precision machined undulator segments. Magnetic data on segments with 20 periods (period length 8.80mm) will be presented. (ii) For hybrid undulators the sorting has to be done on individual poles and magnets. For this approach typical error sources such as machining tolerances, magnetization errors of the permanent magnet material and assembly errors are modeled in 3D and compared to induced errors on an existing hybrid undulator segment. In case of undulators having a full length of hundred periods at least five times as many individual parts have to be characterized. This should be done automatically where both the mechanical and magnetic data before and after the assembly of the magnetic structure are recorded in one step. A CNC programmable measuring device suitable for this task will shortly be presented.

  7. A Coherent Compton Backscattering High Gain FEL using an X-Band Microwave Undulator

    CERN Document Server

    Pellegrini, C; Travish, G

    2005-01-01

    We describe a proposed high-gain FEL using an X-band microwave undulator and operating at a wavelength of about 0.5 μm. The FEL electron beam energy is 65 MeV. The beam is produced by the NLCTA X-band linac at SLAC, using an S-band high-brightness photoinjector. The undulator consists of a circular waveguide with an rf wave counter-propagating with respect to the electron beam. The undulator is powered with two high-power X-band klystrons and a dual-moded pulse compressor recently developed at SLAC. This system is capable of delivering flat-top rf pulses of up to 400 ns and a few hundred megawatts. The equivalent undulator period is 1.4 cm, the radius of the circular pipe is 1 cm, and the undulator parameter is about 0.4 for a helical undulator configuration, obtained using two cross-polarized TE modes, or larger for a planar configuration, using one rf polarization. The undulator is about four meters long. The FEL will reach saturation within this distance when operated in a SASE mode. We describe t...

  8. Design parameters of the high gain harmonic generation experiment using Cornell undulator A at the ATF

    International Nuclear Information System (INIS)

    The authors present the design parameters of a high gain harmonic generation (HGHG) FEL experiment to be carried out at the accelerator test facility (ATF) at BNL, in collaboration with APS. This experiment is a proof-of-principle experiment for the DUV-FEL at BNL. In the HGHG experiment they plan to double the frequency of a CO2 seed laser by utilizing a 0.76 m long 9 period undulator (named the Mini Undulator), a 2 m long 60 period undulator (named the Cornell Undulator A), and a 0.3 m electromagnet chicane (the dispersive section). The first undulator will be used in conjunction with the CO2 seed laser to generate a ponderomotive force that will bunch the electron beam. The bunching will then be enhanced by the dispersion section. The second undulator, the Cornell Undulator A, tuned to the second harmonic of the seed laser will serve as the radiator. In the beginning of the radiator the bunched beam will produce coherent emission (characterized by a quadratic growth of the radiated power), then the radiation will be amplified exponentially. They plan to study the evolution of the various radiation growth mechanisms as well as the coherence of the doubled, exponentially amplified radiation

  9. Prediction of radiation levels at critical locations of European XFEL using radiation measurement data from FLASH and shielding concepts for electronic devices

    International Nuclear Information System (INIS)

    On August 2005 the Free Electron Laser in Hamburg (FLASH) commenced its routine operation. Consequently, in summer 2008 the construction of European X-ray Free Electron Laser (XFEL) began at DESY in Hamburg and at the end of 2013 commissioning will start. The XFEL will be driven by a 1.7 km long, 20 GeV, electron linac made of high purity Niobium superconducting RF cavities. The LLRF systems, Klystrons, electrical power supplies, machine diagnostic and control electronics including the linac itself will be housed in a single 5.1 m diameter underground concrete tunnel. High levels of parasitic Bremsstrahlung and photoneutrons are generated during routine linac operation; hence, the sensitive electronic devices will be exposed to those radiation fields, detrimental to functional and physical integrities of modern microelectronic components. We have carried out a rigorous analysis of radiation fields, dose measurements and efficacy testing of radiological shielding materials at selected locations along the FLASH beam line. The results will serve as vital input data for the prediction of radiation levels at critical locations in the XFEL environment and radiation shielding design for the containment of electronic devices (racks) to be installed in the XFEL tunnel. (author)

  10. Long baseline experiments with LOFAR

    CERN Document Server

    Wucknitz, Olaf

    2010-01-01

    I present first results of LOFAR observations with international baselines. An important cornerstone was the detection of the first long-baseline fringes. Their analysis turns out to be extremely useful to investigate and solve a number of technical issues of the instrument. Crude maps of the sky are created from single-baseline delay/fringe-rate spectra and compared with a short-baseline synthesis map. First long-baseline LBA images are shown of the source 3C196, a bright quasar whose sub-components can only be resolved with the long baselines. The corresponding sub-arcsec HBA image does not show the same amount of details yet, but HBA results are expected to improve significantly very soon. The LBA long-baseline image of 3C196 comprises the highest-resolution radio map ever produced at this low frequency.

  11. Biofuels Baseline 2008

    Energy Technology Data Exchange (ETDEWEB)

    Hamelinck, C.; Koper, M.; Berndes, G.; Englund, O.; Diaz-Chavez, R.; Kunen, E.; Walden, D.

    2011-10-15

    The European Union is promoting the use of biofuels and other renewable energy in transport. In April 2009, the Renewable Energy Directive (2009/28/EC) was adopted that set a 10% target for renewable energy in transport in 2020. The directive sets several requirements to the sustainability of biofuels marketed in the frame of the Directive. The Commission is required to report to the European Parliament on a regular basis on a range of sustainability impacts resulting from the use of biofuels in the EU. This report serves as a baseline of information for regular monitoring on the impacts of the Directive. Chapter 2 discusses the EU biofuels market, the production and consumption of biofuels and international trade. It is derived where the feedstock for EU consumed biofuels originally come from. Chapter 3 discusses the biofuel policy framework in the EU and major third countries of supply. It looks at various policy aspects that are relevant to comply with the EU sustainability requirements. Chapter 4 discusses the environmental and social sustainability aspects associated with EU biofuels and their feedstock. Chapter 5 discusses the macro-economic effects that indirectly result from increased EU biofuels consumption, on commodity prices and land use. Chapter 6 presents country factsheets for main third countries that supplied biofuels to the EU market in 2008.

  12. Performance of a hard x-ray undulator at CHESS (invited)

    International Nuclear Information System (INIS)

    A 3.3-cm period Nd-Fe-B hybrid undulator has been designed and successfully operated in the Cornell Electron Storage Ring (CESR). This 2-m-long, 123-pole insertion device is a prototype of one of the undulators planned for the Advanced Photon Source. In dedicated operation, the undulator produced the expected brightness at 5.437 GeV with the fundamental x-ray energy ranging from 4.3 to 7.9 keV corresponding to a change in gap from 1.5 to 2.8 cm

  13. Improvement of optical properties of synchrotron radiation by undulator segmentation and phase control

    International Nuclear Information System (INIS)

    Two simple schemes to improve optical properties of undulator radiation (UR) are reported. One is to suppress the intensity of higher harmonics, and the other is to obtain variable polarization. Both of them are based on a segmentation of undulator and control of the relative phase between segments. A simple analysis of UR emitted from the segmented undulator is made to explain the principle of the two schemes, which is followed by a detailed discussion on the effects of the finite emittance of the electron beam and angular acceptance of the beamline. Several practical examples are shown to reveal the effectiveness of the proposed schemes. (author)

  14. Design and test of a trial undulator for a compact FEL THz radiation source

    International Nuclear Information System (INIS)

    The undulator is the key component in the THz radiation source based on FEL. We created a trial undulator in order to verify the feasibility of property requirements, and the accumulation of engineering experience. With the use of the finite element calculation software OPERA3D, we modify the structural parameters of the undulator gradually to meet the requirements of the peak, width of the good field and first integration. We also proved that the correction magnet could make the field meet the requirement of the second integration by calculation. After fabrication and acceptance, the electron trajectory is calculated based on the measured field. (authors)

  15. 6 cm period Apple-II type elliptically polarized undulator at PLS

    International Nuclear Information System (INIS)

    Pohang Accelerator Laboratory is developing an Elliptically Polarized Undulator (EPU6) to utilize the polarized synchrotron radiation at Pohang Light Source (PLS). EPU6 is an Apple-II type elliptical undulator which changes the polarization of the field by translating the magnet arrays. EPU6 features period of 6 cm, minimum gap of 19 mm, 25 full field periods, maximum vertical flux density of 0.69 T, maximum horizontal flux density of 0.45 T, and 1575 mm total magnetic structure length. In this article, the design, fabrication, the measurement and correction efforts for PLS EPU6 undulator are described

  16. Calculation of undulator radiation from measured magnetic fields and comparison with measured spectra

    International Nuclear Information System (INIS)

    A new code was developed that calculates the spectrum, the state and the degree of polarization of the radiation emitted by any insertion device. It integrates along an arbitrary electron trajectory without any approximations. The trajectory can be derived either from a model undulator including random field errors or from a measured field distribution from a real undulator. The calculated one-electron pattern is convoluted with the electron beam emittance. Spectral calculations for the crossed field undulator U-2 at BESSY employing measured magnetic field data agree with absolute measurements of the spectra. (author) 18 refs.; 1 fig

  17. Undulator system for the VUV FEL at the TESLA test facility phase-2

    Science.gov (United States)

    Pflüger, J.; Hahn, U.; Faatz, B.; Tischer, M.

    2003-07-01

    The Phase-1 of the VUV Free Electron Laser at the TESLA Test Facility finishes in fall 2002. Phase-2, an extension of Phase-1 towards shorter wavelengths is under construction and will be ready for operation in 2003. A radiation wavelength as low as 6 nm will be obtained by raising the electron energy to 1 GeV. There will be only minor changes to the undulator system. Compared to Phase-1, six instead of three undulator segments will be installed. The integrated focusing system will be replaced by an electromagnetic doublet structure. We report about the changes of the undulator, the undulator vacuum system, the separated quadrupoles including a stretched wire alignment systems and the modifications to the beam diagnostic system consisting of pick up monitors and wire scanners.

  18. Undulator system for the VUV FEL at the TESLA test facility phase-2

    International Nuclear Information System (INIS)

    The Phase-1 of the VUV Free Electron Laser at the TESLA Test Facility finishes in fall 2002. Phase-2, an extension of Phase-1 towards shorter wavelengths is under construction and will be ready for operation in 2003. A radiation wavelength as low as 6 nm will be obtained by raising the electron energy to 1 GeV. There will be only minor changes to the undulator system. Compared to Phase-1, six instead of three undulator segments will be installed. The integrated focusing system will be replaced by an electromagnetic doublet structure. We report about the changes of the undulator, the undulator vacuum system, the separated quadrupoles including a stretched wire alignment systems and the modifications to the beam diagnostic system consisting of pick up monitors and wire scanners

  19. Start-to-end global imaging as a sunward propagating, SAPS-associated giant undulation event

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Michael G [Los Alamos National Laboratory; Donovan, Eric F [U OF CALGARY; Foster, John C [MIT; Mann, Ian R [UNIV OF ALBERTA; Immel, Thomas J [UC/BERKELEY; Mende, Stephen B [UN/BERKELEY; Sigwarth, John B [NASA/GSFC

    2009-01-01

    We present high-time resolution global imaging of a sunward propagating giant undulation event from start to finish. The event occurred on November 24, 2001 during a very disturbed storm interval. The giant undulations began to develop at around 13UT and persisted for approximately 2 hours. The sunward propagation speed was on the order of 0.6 km/s (relative to SM coordinate system). The undulations had a wavelength of {approx} 750 km, amplitudes of {approx} 890 km and produced ULF pulsations on the ground with a period of {approx} 1108s. We show that the undulations were associated with SAPs flows that were caused by the proton plasma sheet penetrating substantially farther Earthward than the electron plasma sheet on the duskside. The observations appear to be consistent with the development of a shear flow and/or ballooning type of instability at the plasmapause driven by intense SAPS-associated shear flows.

  20. Empirical Optimization of Undulator Tapering at FLASH2 and Comparison with Numerical Simulations

    CERN Document Server

    Mak, Alan; Faatz, Bart; Werin, Sverker

    2016-01-01

    In a free-electron laser equipped with variable-gap undulator modules, the technique of undulator tapering opens up the possibility to increase the radiation power beyond the initial saturation point, thus enhancing the efficiency of the laser. The effectiveness of the enhancement relies on the proper optimization of the taper profile. In this work, a multidimensional optimization approach is implemented empirically in the x-ray free-electron laser FLASH2. The empirical results are compared with numerical simulations.

  1. A review of undulated sediment features on Mediterranean prodeltas: distinguishing sediment transport structures from sediment deformation

    OpenAIRE

    Urgeles, Roger; Cattaneo, Antonio; PUIG Pere; Liquete, Camino; Mol, Ben; Amblas, David; Sultan, Nabil; Trincardi, Fabio

    2011-01-01

    Most Mediterranean prodeltas show undulated sediment features on the foresets of their Holocene wedges. These features have been described all along the Mediterranean for the last 30 years and interpreted as either soft sediment deformation and incipient landsliding, and more recently, as sediment transport structures. We perform a review and detailed analysis of these undulated sediment features using ultrahigh-resolution seismic and bathymetric data as well as geotechnical information and h...

  2. Brightness and coherence of radiation from undulators and high-gain free electron lasers

    International Nuclear Information System (INIS)

    The purpose of this paper is to review the radiation characteristics of undulators and high-gain free electron lasers (FELs). The topics covered are: a phase-space method in wave optics and synchrotron radiation, coherence from the phase-space point of view, discussions of undulator performances in next-generation synchrotron radiation facility and the characteristics of the high-gain FELs and their performances

  3. Development of beam halo monitors for the European XFEL using radiation hard sensors and demonstration of the technology at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Ignatenko, Alexandr

    2015-05-15

    The European X-Ray Free-Electron Laser (E-XFEL), currently under construction in Hamburg, Germany, is intended to be an international linear accelerator (linac) based user facility. Its electron beam can carry maximal average power of 600 kW. A beam with such a high power needs to be carefully transmitted through the machine and safely dumped after utilization. This is supported by various diagnostics tools. A Beam Halo Monitor (BHM) based on synthetic diamond and sapphire sensors has been designed. Diamond sensors are developed by the company element6 for the detection of ionizing radiation and used previously elsewhere. Sapphire sensors are in this thesis applied for the first time. The BHM concept has been applied already at the Free-electron Laser in Hamburg (FLASH). A module with four diamond and four sapphire sensors was designed, installed inside the beam pipe, commissioned, calibrated and has been successfully operated for 4 years. The system contributed significantly to safe and efficient operation of FLASH. Both types of the sensors for the BHM were characterized. Measurements of radiation tolerance are done in a 10 MeV electron beam for polycrystalline CVD (pCVD) diamond sensors for the first time up to a dose of 10 MGy and for sapphire sensors up to 5 MGy. The charge collection efficiency (CCE) drops as a function of the absorbed dose, is however still sufficient for application as a BHM. To improve a main sensor characteristic, the charge collection efficiency, for sapphire sensors the impurity concentration was reduced and different growth techniques were compared. Finally, charge collection efficiency of about 5 % for a bias voltage of 500 V was reached. The BHM concept for the XFEL is designed and in the construction phase.

  4. Beam Diagnostics for Laser Undulator Based on Compton Backward Scattering

    CERN Document Server

    Kuroda, R

    2005-01-01

    A compact soft X-ray source is required in various research fields such as material and biological science. The laser undulator based on Compton backward scattering has been developed as a compact soft X-ray source for the biological observation at Waseda University. It is performed in a water window region (250eV - 500 eV) using the interaction between 1047 nm Nd:YLF laser (10ps FWHM) and about 5 MeV high quality electron beam (10ps FWHM) generated from rf gun system. The range of X-ray energy in the water window region has K-shell absorption edges of Oxygen, Carbon and Nitrogen, which mainly constitute of living body. Since the absorption coefficient of water is much smaller than the protein's coefficient in this range, a dehydration of the specimens is not necessary. To generate the soft X-ray pulse stably, the electron beam diagnostics have been developed such as the emittance measurement using double slit scan technique, the bunch length measurement using two frequency analysis technique. In this confere...

  5. Geometric Mechanics Reveals Optimal Complex Terrestrial Undulation Patterns

    Science.gov (United States)

    Gong, Chaohui; Astley, Henry; Schiebel, Perrin; Dai, Jin; Travers, Matthew; Goldman, Daniel; Choset, Howie; CMU Team; GT Team

    Geometric mechanics offers useful tools for intuitively analyzing biological and robotic locomotion. However, utility of these tools were previously restricted to systems that have only two internal degrees of freedom and in uniform media. We show kinematics of complex locomotors that make intermittent contacts with substrates can be approximated as a linear combination of two shape bases, and can be represented using two variables. Therefore, the tools of geometric mechanics can be used to analyze motions of locomotors with many degrees of freedom. To demonstrate the proposed technique, we present studies on two different types of snake gaits which utilize combinations of waves in the horizontal and vertical planes: sidewinding (in the sidewinder rattlesnake C. cerastes) and lateral undulation (in the desert specialist snake C. occipitalis). C. cerastes moves by generating posteriorly traveling body waves in the horizontal and vertical directions, with a relative phase offset equal to +/-π/2 while C. occipitalismaintains a π/2 offset of a frequency doubled vertical wave. Geometric analysis reveals these coordination patterns enable optimal movement in the two different styles of undulatory terrestrial locomotion. More broadly, these examples demonstrate the utility of geometric mechanics in analyzing realistic biological and robotic locomotion.

  6. Baseline Familiarity in Lie Detection.

    Science.gov (United States)

    Feeley, Thomas H.; And Others

    1995-01-01

    Reports on a study in which subjects judged the veracity of truthful and deceptive communicators after viewing no, one, two, or four case-relevant baseline exposures (familiarity) of truthful communication. Finds a positive linear relationship between detection accuracy and amount of baseline familiarity. (SR)

  7. Misconception regarding conventional coupling of fields and particles in XFEL codes

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [Europeam XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [DESY Hamburg (Germany)

    2016-01-15

    Maxwell theory is usually treated in the laboratory frame under the standard time order, that is the usual light-signal clock synchronization. In contrast, particle tracking in the laboratory frame usually treats time as an independent variable. As a result, here we argue that the evolution of electron beams is usually treated according to the absolute time convention i.e. using a different time order defined by a non-standard clock synchronization procedure. This essential point has never received attention in the accelerator community. There are two possible ways of coupling fields and particles in this situation. The first, Lorentz's prerelativistic way, consists in a 'translation' of Maxwell's electrodynamics to the absolute time world-picture. The second, Einstein's way, consists in a 'translation' of particle tracking results to the electromagnetic world-picture, obeying the standard time order. Conventional particle tracking shows that the electron beam direction changes after a transverse kick, while the orientation of the microbunching phase front stays unvaried. Here we show that in the ultrarelativistic asymptotic v → c, the orientation of the planes of simultaneity, i.e. the orientation of the microbunching fronts, is always perpendicular to the electron beam velocity when the evolution of the modulated electron beam is treated under Einstein's time order. This effect allows for the production of coherent undulator radiation from a modulated electron beam in the kicked direction without suppression. We hold a recent FEL study at the LCLS as a direct experimental evidence that the microbunching wavefront indeed readjusts its direction after the electron beam is kicked by a large angle, limited only by the beamline aperture. In a previous paper we quantitatively described this result invoking the aberration of light effect, which corresponds to Lorentz's way of coupling fields and particles. The purpose of

  8. Program cost and schedule baseline

    International Nuclear Information System (INIS)

    The overall purpose of cost and schedule baseline management is to ensure that the Civilian Radioactive Waste Management (OCRWM) Program's cost and schedule plan are controlled in an orderly, efficient, and documented manner. Baseline control of the Program's cost and schedule will result in changes that only take place with OCRWM senior management approval, by way of the change control process. The Program Management System (PMS) Manual describes how the Program Cost and Schedule Baseline (PCSB) is integrated into the OCRWM management system. This PCSB document identifies the components of Program cost and schedule that will be subject to change control by DOE-Headquarters and establishes their baseline values. This document also summarizes the management components of the cost and schedule baseline, including reporting, monitoring, and corrective action. Detailed PCSB reporting, monitoring, and corrective action procedures will be issued as an Office of Program Administration and Resource Management (OPARM) administrative procedure. 9 figs

  9. Plutonium Immobilization Project Baseline Formulation

    Energy Technology Data Exchange (ETDEWEB)

    Ebbinghaus, B.

    1999-02-01

    A key milestone for the Immobilization Project (AOP Milestone 3.2a) in Fiscal Year 1998 (FY98) is the definition of the baseline composition or formulation for the plutonium ceramic form. The baseline formulation for the plutonium ceramic product must be finalized before the repository- and plant-related process specifications can be determined. The baseline formulation that is currently specified is given in Table 1.1. In addition to the baseline formulation specification, this report provides specifications for two alternative formulations, related compositional specifications (e.g., precursor compositions and mixing recipes), and other preliminary form and process specifications that are linked to the baseline formulation. The preliminary specifications, when finalized, are not expected to vary tremendously from the preliminary values given.

  10. Scheme for generating and transporting THz radiation to the X-ray experimental floor at LCLS baseline

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-08-15

    This paper describes a novel scheme for integrating a coherent THz source in the baseline of the LCLS facility. Any method relying on the spent electron beam downstream of the baseline undulator should provide a way of transporting the radiation up to the experimental floor.Herewe propose to use the dump area access maze. In this way the THz output must propagate with limited size at least for one hundred meters in a maze, following many turns, to reach the near experimental hall. The use of a standard, discrete, open beam-waveguide formed by periodic reflectors, that is a mirror guide, would lead to unacceptable size of the system. To avoid these problems, in this paper we propose an alternative approach based on periodically spaced metallic screens with holes. This quasi-optical transmission line is referred to as an iris line. We present complete calculations for the iris line using both analytical and numerical methods, which we find in good agreement. We present a design of a THz edge radiation source based on the use of an iris line. The proposed setup takes almost no cost nor time to be implemented at the LCLS baseline, and can be used at other facilities as well. The edge radiation source is limited in maximally achievable field strength at the sample. An extension based on the use of an undulator in the presence of the iris line, which is feasible at the LCLS energies, is proposed as a possible upgrade of the baseline THz source. (orig)

  11. Location for new research facility determined X-ray laser XFEL to be realized in the federal states of Hamburg and Schleswig-Holstein starting in 2006

    CERN Multimedia

    2003-01-01

    "...The site for the XFEL has now been determined by the research center DESY (Deutsches Elektronen-Synchrotron); it was announced today at a press conference in Hamburg. The 3.3-kilometer-long facility is to be located in the federal states of Hamburg and Schleswig-Holstein. It will begin on the DESY site in Hamburg-Bahrenfeld and run in a north-western direction to the town of Schenefeld (district of Pinneberg), which borders on Hamburg" (1 page).

  12. 324 Building Baseline Radiological Characterization

    Energy Technology Data Exchange (ETDEWEB)

    R.J. Reeder, J.C. Cooper

    2010-06-24

    This report documents the analysis of radiological data collected as part of the characterization study performed in 1998. The study was performed to create a baseline of the radiological conditions in the 324 Building.

  13. Quivira NWR biological baseline data

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This dataset is biological baseline data for Quivira National Wildlife Refuge as of January 2016. It contains data on species found on the refuge, when and where...

  14. Learning to Baseline Business Technology

    OpenAIRE

    David Gore; Marie D. Lee; Kimberly Hopper

    2013-01-01

    bills, sign multi-­‐year contracts, and make purchasing decisions without having an overall technology plan. That plan includes a technology baseline to fully assess existing technology. A CIO's goal is to align IT with business goals. Businesses must know total cost of ownership and the return on investment for all technology purchases and monthly costs. A business must also be able to manage technology assets and best utilize resources across the business. Teaching students to baseline tech...

  15. Magnetic characterization of the undulator for infrared free-electron laser at RRCAT

    International Nuclear Information System (INIS)

    An infrared (IR) free electron laser (FEL) is currently under development at the RRCAT, Indore. One of the crucial components of an FEL is the undulator, which produces static, sinusoidal vertical magnetic field along the axis through which an electron beam is propagated to generate coherent radiation. A 2.5 m long, pure permanent magnet based undulator with a period of 50 mm has been recently procured and installed at its designated location inside the radiation shielded area built to house the IRFEL. For the successful operation of an FEL, the magnetic field profile of the undulator has to satisfy stringent criterion on parameters such as rms error in the peak field, optical phase error, trajectory errors etc. Detailed magnetic characterization of the undulator installed inside the shielded area has been performed using in-house developed measurement benches to measure the magnetic field profile as well as magnetic field integrals. This paper describes the details of magnetic characterization performed to ensure that all the required criteria on the field quality are satisfied by the undulator. (author)

  16. Measurement of position and profile of undulator radiation in Indus-2 using scanning wire monitor

    International Nuclear Information System (INIS)

    Two planar undulators (U1 and U2) for Atomic Molecular Spectroscopy (AMOS) beamline and Angle Resolved Photoelectron Spectroscopy (ARPES) beamline have been installed in Indus-2. The U1 undulator is designed to produce photons in the energy range of 6 eV to 250 eV and U2 undulator is designed to produce photons in the energy range of 30 eV to 600 eV. In order to measure the position and vertical profile of photon beams emitted from these undulators, one scanning wire monitor has been installed in each beamline front end. In these scanning wire monitors, a gold coated tungsten wire of 100 μm thickness, stretched between a fork shaped alumina ceramic holder, is scanned vertically perpendicular to the direction of propagation of photon beam by using a precisely controlled stepper motor. The photo-electron current generated in the wire is measured by an electrometer. A graphical user interface has been developed which facilitates the scanning as per the given range, plots the graphs and stores the scanned data in Excel file. This paper describes our experience and usefulness of these wire monitors during commissioning of planar undulators in Indus-2. (author)

  17. Spectral properties of segmented undulators for the 7-GeV advanced photon source

    International Nuclear Information System (INIS)

    The effect of nonzero particle beam emittance and magnetic field errors on the on-axis spectral brightness (BTo) of long undulators is discussed. It is shown that the quadratic dependence of BTo on the number of undulator periods, N, is reduced by emittance to N-x with 1 ≤x < 2. Further reductions in the intensity result from random magnetic field errors present in the undulator. An approximate model for the intensity of the central core of radiation of the principle harmonics is discussed and the results compared to those from Monte Carlo-type calculations where emittance is explicitly accounted for. An estimation of the effects of random field errors on the on-axis brightness in the presence of nonzero particle emittance is made. For the particular case of undulators proposed for the 7-GeV Advanced Photon Source, the results indicate that 5-m-long devices segmented into two sections will provide the required spectral intensity of a single long undulator when both emittance and magnet errors are considered

  18. APPLE-II type quasi-periodic variably polarizing undulator at HiSOR

    International Nuclear Information System (INIS)

    A 1.8-m-long 78-mm-period quasi-periodic APPLE-II undulator was installed in the 700-MeV HiSOR storage ring of Hiroshima Synchrotron Radiation Center. At the nominal minimum gap, achievable lowest photon energies are 3.1 eV, 6.5 eV, and 4.8 eV for horizontal linear, vertical linear, and circular polarization, respectively. Observed photon energies of fundamental and higher harmonic radiations are in good agreement with those of model calculations using measured magnetic field of undulator and the HiSOR beam parameters. Also, observed flux thorough a slit and a grating monochromator was more than twice larger than that from previously installed 100-mm-period helical undulator for the whole range of radiation spectra. The feedforward COD correction was done to avoid the intensity fluctuation of photon beam in other beamlines due to the gap and phase motion of undulator. No fatal effect on the stored electron beam by installing the undulator was observed though a slight beam size change was observed at the minimum gap. (author)

  19. Nonintrusive methodology for wellness baseline profiling

    Science.gov (United States)

    Chung, Danny Wen-Yaw; Tsai, Yuh-Show; Miaou, Shaou-Gang; Chang, Walter H.; Chang, Yaw-Jen; Chen, Shia-Chung; Hong, Y. Y.; Chyang, C. S.; Chang, Quan-Shong; Hsu, Hon-Yen; Hsu, James; Yao, Wei-Cheng; Hsu, Ming-Sin; Chen, Ming-Chung; Lee, Shi-Chen; Hsu, Charles; Miao, Lidan; Byrd, Kenny; Chouikha, Mohamed F.; Gu, Xin-Bin; Wang, Paul C.; Szu, Harold

    2007-04-01

    We develop an accumulatively effective and affordable set of smart pair devices to save the exuberant expenditure for the healthcare of aging population, which will not be sustainable when all the post-war baby boomers retire (78 millions will cost 1/5~1/4 GDP in US alone). To design an accessible test-bed for distributed points of homecare, we choose two exemplars of the set to demonstrate the possibility of translation of modern military and clinical know-how, because two exemplars share identically the noninvasive algorithm adapted to the Smart Sensor-pairs for the real world persistent surveillance. Currently, the standard diagnoses for malignant tumors and diabetes disorders are blood serum tests, X-ray CAT scan, and biopsy used sometime in the physical checkup by physicians as cohort-average wellness baselines. The loss of the quality of life in making second careers productive may be caused by the missing of timeliness for correct diagnoses and easier treatments, which contributes to the one quarter of human errors generating the lawsuits against physicians and hospitals, which further escalates the insurance cost and wasteful healthcare expenditure. Such a vicious cycle should be entirely eliminated by building an "individual diagnostic aids (IDA)," similar to the trend of personalized drug, developed from daily noninvasive intelligent databases of the "wellness baseline profiling (WBP)". Since our physiology state undulates diurnally, the Nyquist anti-aliasing theory dictates a minimum twice-a-day sampling of the WBP for the IDA, which must be made affordable by means of noninvasive, unsupervised and unbiased methodology at the convenience of homes. Thus, a pair of military infrared (IR) spectral cameras has been demonstrated for the noninvasive spectrogram ratio test of the spontaneously emitted thermal radiation from a normal human body at 37°C temperature. This invisible self-emission spreads from 3 microns to 12 microns of the radiation wavelengths

  20. Design, construction and characterization of the compact ultrafast terahertz free-electron laser undulator

    Indian Academy of Sciences (India)

    B Biswas; V Kumar; S Chouksey; S Krishnagopal

    2008-12-01

    A compact ultrafast terahertz (CUTE) free-electron laser (FEL) is being developed at the Raja Ramanna Centre for Advanced Technology (RRCAT), Indore. The undulator required for the CUTE-FEL has recently been developed. We have designed, built and characterized a variable gap, 5 cm period, 2.5 m long pure permanent magnet undulator in two identical segments. The tolerable error in the magnetic field was 1% in rms, and we have measured it to be 0.7%. The obtained rms phase shake is around 2°. To ensure that the trajectories do not have an exit error in position or angle, corrector coils have been designed. Shimming coils have been applied for both the undulator segments to reduce the amplitude of the betatron oscillations in the vertical trajectory. Details of novel corrector coils and soft iron shims are given and their performance is discussed.

  1. Locomotion and Depth Control of Robotic Fish with Modular Undulating Fins

    Institute of Scientific and Technical Information of China (English)

    Kin Huat Low

    2006-01-01

    This paper presents an environmental-friendly robotic system mimicking the undulating fins of a fish. To mimic the actual flexible fin of real fish, a fin-like mechanism with a series of connecting linkages is modeled and attached to the robotic fish, by virtue of a specially designed strip. Each link is able to turn and slide with respect to the adjacent link.These driving linkages are then used to form a mechanical fin consisting of several fin segments, which are able to produce undulations, similar to those produced by the actual fish fins. Owing to the modular and re-configurable design of the mechanical fin, we are able to construct biomimetic robotic fish with various swimming modes by fin undulations. Some qualitative and workspace observations by experiments of the robotic fish are shown and discussed.

  2. Nearly copropagating sheared laser pulse FEL undulator for soft x-rays

    International Nuclear Information System (INIS)

    A conceptual design for a soft x-ray free-electron laser (FEL) using a short-pulsed, high energy near infrared laser undulator and a low-emittance modest-energy (∼170 MeV) electron beam is described. This low-cost design uses the laser undulator beam in a nearly copropagating fashion with respect to the electron beam, instead of the traditional ‘head-on’ fashion. The nearly copropagating geometry reduces the Doppler shift of scattered radiation to yield soft, rather than hard x-rays. To increase the FEL gain a sheared laser pulse from a Ti : sapphire or other broadband laser is used to extend the otherwise short interaction time of the nearly copropagating laser undulator beam with a relativistic electron beam. (paper)

  3. An ultracompact X-ray source based on a laser-plasma undulator

    Science.gov (United States)

    Andriyash, I. A.; Lehe, R.; Lifschitz, A.; Thaury, C.; Rax, J.-M.; Krushelnick, K.; Malka, V.

    2014-08-01

    The capability of plasmas to sustain ultrahigh electric fields has attracted considerable interest over the last decades and has given rise to laser-plasma engineering. Today, plasmas are commonly used for accelerating and collimating relativistic electrons, or to manipulate intense laser pulses. Here we propose an ultracompact plasma undulator that combines plasma technology and nanoengineering. When coupled with a laser-plasma accelerator, this undulator constitutes a millimetre-sized synchrotron radiation source of X-rays. The undulator consists of an array of nanowires, which are ionized by the laser pulse exiting from the accelerator. The strong charge-separation field, arising around the wires, efficiently wiggles the laser-accelerated electrons. We demonstrate that this system can produce bright, collimated and tunable beams of photons with 10-100 keV energies. This concept opens a path towards a new generation of compact synchrotron sources based on nanostructured plasmas.

  4. An ultracompact X-ray source based on a laser-plasma undulator.

    Science.gov (United States)

    Andriyash, I A; Lehe, R; Lifschitz, A; Thaury, C; Rax, J-M; Krushelnick, K; Malka, V

    2014-01-01

    The capability of plasmas to sustain ultrahigh electric fields has attracted considerable interest over the last decades and has given rise to laser-plasma engineering. Today, plasmas are commonly used for accelerating and collimating relativistic electrons, or to manipulate intense laser pulses. Here we propose an ultracompact plasma undulator that combines plasma technology and nanoengineering. When coupled with a laser-plasma accelerator, this undulator constitutes a millimetre-sized synchrotron radiation source of X-rays. The undulator consists of an array of nanowires, which are ionized by the laser pulse exiting from the accelerator. The strong charge-separation field, arising around the wires, efficiently wiggles the laser-accelerated electrons. We demonstrate that this system can produce bright, collimated and tunable beams of photons with 10-100 keV energies. This concept opens a path towards a new generation of compact synchrotron sources based on nanostructured plasmas. PMID:25145401

  5. Development of Control System for Fast Frequency Tuners of Superconducting Resonant Cavities for FLASH and XFEL Experiments

    CERN Document Server

    Przygoda, K

    2011-01-01

    This dissertation covers the recent research and development (R&D) activities of control systems for the fast frequency tuners of TESLA cavities and predicts the implications foreseen for large scale machines such as the FLASH and the planned XFEL. In particular, the framework of the presented activities is the effort toward the: 1. R&D of the driving circuit, 2. R&D of the control algorithm, 3. R&D of the control system. The main result of these activities is the permanent installation of the target piezo control system and its commissioning for 40 cavities divided into 5 accelerating modules at the DESY FLASH facility. The author’s contribution was the study of possible designs of high-voltage, high-current power amplifiers, used for driving the fast frequency tuners, shows that several parameters of such a device needs to be considered. The most important parameter is the input and output power estimation. This arises from the fact that the estimation is the most crucial issue for both po...

  6. Bunch arrival time monitors; Concepts towards improving the sensitivity for low charge operation for FLASH II and XFEL

    International Nuclear Information System (INIS)

    High gain Free-Electron Lasers can generate ultra short X-ray pulses in the femtosecond range. For a stable operation of the FEL, the precise knowledge of the bunch arrival time is crucial. A novel high bandwidth Bunch Arrival time Monitor was recently installed at FLASH to allow a low charge operation mode with a sub-10 fs resolution for bunch charges of 20 pC or more. The BAM is equipped with cone shaped pickups for the precise measurement of both, the high and low bunch charge operation mode. For the extension of FLASH facility to FLASH II new pickups for the high bandwidth BAMs need to be developed. The new BAM needs to maximize the voltage level of the beam induced signal for low charge operation mode in order to provide sufficient signal strength for the subsequent electronics. In this talk, we present concepts to improve the signal strength at the electro-optic modulators for low charge operation at FLASH II and XFEL.

  7. Developing RESRAD-BASELINE for environmental baseline risk assessment

    International Nuclear Information System (INIS)

    RESRAD-BASELINE is a computer code developed at Argonne developed at Argonne National Laboratory for the US Department of Energy (DOE) to perform both radiological and chemical risk assessments. The code implements the baseline risk assessment guidance of the US Environmental Protection Agency (EPA 1989). The computer code calculates (1) radiation doses and cancer risks from exposure to radioactive materials, and (2) hazard indexes and cancer risks from exposure to noncarcinogenic and carcinogenic chemicals, respectively. The user can enter measured or predicted environmental media concentrations from the graphic interface and can simulate different exposure scenarios by selecting the appropriate pathways and modifying the exposure parameters. The database used by PESRAD-BASELINE includes dose conversion factors and slope factors for radionuclides and toxicity information and properties for chemicals. The user can modify the database for use in the calculation. Sensitivity analysis can be performed while running the computer code to examine the influence of the input parameters. Use of RESRAD-BASELINE for risk analysis is easy, fast, and cost-saving. Furthermore, it ensures in consistency in methodology for both radiological and chemical risk analyses

  8. Knot undulator to generate linearly polarized photons with low on-axis power density.

    Science.gov (United States)

    Qiao, S; Ma, Dewei; Feng, Donglai; Marks, S; Schlueter, R; Prestemon, S; Hussain, Z

    2009-08-01

    Heat load on beamline optics is a serious obstacle for devices designed to generate pure linearly polarized photons in third generation synchrotron radiation facilities. For permanent magnet undulators, this problem can be overcome by implementing a figure-eight design configuration. As yet there has been no good method to tackle this problem for electromagnetic elliptical undulators. Here, a novel design and operational mode is suggested, which can generate pure linearly polarized photons with very low on-axis heat load. Additionally, the minimum photon energy capability of linearly polarized photons can be significantly extended by this method. PMID:19725682

  9. High efficiency energy extraction from a relativistic electron beam in a strongly tapered undulator

    CERN Document Server

    Sudar, Nicholas; Duris, Joe; Gadjev, Ivan; Polyaniy, Mikhail; Pogorelsky, Igor; Fedurin, Mikhail; Swinson, Christina; Babzien, Marcus; Kusche, Karl; Gover, Avi

    2016-01-01

    We present results of an experiment where, using a 200 GW CO2 laser seed, a 65 MeV electron beam was decelerated down to 35 MeV in a 54 cm long strongly tapered helical magnetic undulator, extracting over 30$\\%$ of the initial electron beam energy to coherent radiation. These results demonstrate unparalleled electro-optical conversion efficiencies for a relativistic beam in an undulator field and represent an important step in the development of high peak and average power coherent radiation sources.

  10. Knot undulator to generate linearly polarized photons with low on-axis power density

    International Nuclear Information System (INIS)

    Heat load on beamline optics is a serious obstacle for devices designed to generate pure linearly polarized photons in third generation synchrotron radiation facilities. For permanent magnet undulators, this problem can be overcome by implementing a figure-eight design configuration. As yet there has been no good method to tackle this problem for electromagnetic elliptical undulators. Here, a novel design and operational mode is suggested, which can generate pure linearly polarized photons with very low on-axis heat load. Additionally, the minimum photon energy capability of linearly polarized photons can be significantly extended by this method.

  11. Light's orbital angular momentum carried by helical undulator harmonics

    International Nuclear Information System (INIS)

    Spiral interference patterns between two different harmonic radiations from two tandem-aligned helical undulators were observed by a scanning fiber multi-channel spectrometer and a UV-CCD camera placed at the end of beamline downstream of S1 straight section in UVSOR-III. Using these measurements, various interference patterns such as single, double, and triple spirals were observed which concur with the theoretical predictions for every mode in the right or left circular polarization. The rotation of an interference pattern by rotating a polarizer was also observed. In this article, a theoretical background and a series of experimental results are described for the exotic property of undulator harmonics. (author)

  12. Observation of light's orbital angular momentum from helical undulator harmonics

    International Nuclear Information System (INIS)

    A spiral interference pattern between fundamental and second harmonic radiations form two tandem-aligned helical undulators was observed by scanning a fiber multi-channel spectrometer placed at the end of beamline downstream of S1 straight section in UVSOR. With these experiments, interference patterns were in good agreement with those by theoretical prediction for right and left circular polarization modes. Also, similar interference measurement was done by using a CCD camera. With this measurement, we observed a rotation of spiral pattern by changing the undulator gap. (author)

  13. Observation of Electron Clouds in the ANKA Undulator by Means of the Microwave Transmission Method

    CERN Document Server

    Sonnad, K G; Casalbuoni, S; Huttel, E; Mashkina, E M; Saez de Jauregui, D; Smale, N J; Caspers, Friedhelm; Muller, A S; Sonnad, K G; Weigel, R

    2010-01-01

    A superconducting undulator is installed in the ANKA electron storage ring. Electron clouds could potentially contribute to the heat load of this device. A microwave transmission type electron cloud diagnostic has been installed for the undulator section of the ANKA machine. We present the system layout with particular emphasis on the electron machine aspects. Hardware transfer function results and e-cloud data for different machine settings are discussed. Special care has been taken for front end filter design both on the microwave injection and pick-up side.

  14. A new undulator for the extension of the spectral range of the CLIO FEL

    Energy Technology Data Exchange (ETDEWEB)

    Marcouille, O.; Berset, J.M.; Glotin, F. [LURE, Orsay (France)] [and others

    1995-12-31

    We built a new undulator in order to extend the lasing range of the CLIO infrared FEL. Presently, CLIO operates in the wavelength range 2 - 17 {mu}m. Beyond 14 {mu}m, the power decreases rapidly, because of the diffraction losses of the vacuum chamber (7 mm height and 2 m long). Thus, lasing at higher wavelengths implies installing a chamber with a height approximately twice. Then the minimum gap is increased and the maximum deflection parameter, K, is reduced from 2 to 1 : the laser tunability is greatly reduced. This is why a new undulator has been built.

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

    OpenAIRE

    Anania, M.P.; Brunetti, E; Wiggins, S M; Grant, D W; Welsh, G. H.; Issac, R.C.; Cipiccia, S.; Shanks, R. P.; Manahan, G. G.; Aniculaesei, C.; van der Geer, S. B.; De Loos, M.J.; Poole, M.W.; Shepherd, B. J. A.; Clarke, J A

    2014-01-01

    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 × 106 per shot for a 100 period undulator, with a mean peak brilliance of 1 × 1018 photons/s/mrad2/mm2/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has ...

  16. Operation of a small-gap undulator on the NSLS X-ray Ring

    Energy Technology Data Exchange (ETDEWEB)

    Stefan, P.M.; Krinsky, S.; Rakowsky, G.; Solomon, L. [Brookhaven National Lab., Upton, NY (United States)

    1995-02-01

    The authors report results of an on-going experiment being carried out in the X13 straight section of the NSLS X-ray Ring which explores the limits of the operation of small-gap undulators. In particular, they discuss the operation of a 16 mm period small-gap undulator. At an electron beam current of 300 mA the variable gap vacuum chamber has been closed to an inner aperture of 3.8 mm with no effect on the electron beam lifetime. Measurements of the output radiation spectrum at a magnet gap of 7.5 mm are described.

  17. Comparison of different undulator schemes with superimposed alternating gradients for the VUV-FEL at the TESLA Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Pflueger, J.; Nikitina, Y.M. [DESY/HASYLAB, Hamburg (Germany)

    1995-12-31

    For the VUV-FEL at the TESLA Test Facility an undulator with a total length of 30 m is needed. In this study three different approaches to realize an undulator with a sinusoidal plus a superimposed quadrupolar field were studied with the 3D code MAFIA.

  18. Sea-floor undulations formation by turbidity flow in the Adra prodeltaic system, western Mediterranean Basin: comparison between numerical simulation and real data

    Science.gov (United States)

    Fernández-Salas, Luis Miguel; Barcenas, Patricia; Macias, Jorge

    2016-04-01

    Numerical simulation of turbidity currents are used to study the formation of the seafloor undulations in the Adra prodeltaic system, western Mediterranean basin. A series of elongated and subparallel bathymetric undulations are distinguished in the foreset-bottomsets domain of the Holocene pro-deltaic wedge associated with the Adra river. In this study, multibeam data and surficial sediment samples have been used in comparison with numerical simulation to propose an evolutionary model of the seafloor undulations. Numerical model suggests that the depositional basin slope gradient is one of the factors more influent in the seafloor undulations formation. The simulations allowed to observe as seafloor undulations are approximately in phase with the undulations of the turbidity layer. Therefore, undulations are associated with Froude-supercritical flow. The upslope and downslope undulations boundaries are limited by a hydraulic jump where the flow makes a conversion from supercriticial flow (Fr>1) to subcritical flow (Frproject TESELA (P11-RNM7069)

  19. Integrated Baseline Review (IBR) Handbook

    Science.gov (United States)

    2013-01-01

    An Integrated Baseline Review (IBR) is a review of a supplier?s Performance Measurement Baseline (PMB). It is conducted by Program/Project Managers and their technical staffs on contracts and in-house work requiring compliance with NASA Earned Value Management System (EVMS) policy as defined in program/project policy, NPR 7120.5, or in NASA Federal Acquisition Regulations. The IBR Handbook may also be of use to those responsible for preparing the Terms of Reference for internal project reviews. While risks may be identified and actions tracked as a result of the IBR, it is important to note that an IBR cannot be failed.

  20. Design, fabrication, installation and commissioning of water-cooled beam viewer for undulator front-ends of Indus-2

    International Nuclear Information System (INIS)

    A water-cooled beam viewer is developed indigenously to observe the bright synchrotron light coming from recently installed undulators in Indus-2 storage ring at RRCAT, Indore. The beam viewer is installed in the undulator front-end. The frontend is a long ultra high vacuum (UHV) assembly consisting of UHV valves, shutters, vacuum pumps and beam diagnostic devices. The front-end acts as an interface between Indus-2 ring and beamline. The beam viewer uses a fluorescent sheet of Chromium doped Alumina (CHROMOX) which produces visible fluorescent light when bright synchrotron light from the undulator falls on it. This visible fluorescent light is observed through a glass window by a CCD camera. The beam viewer has been successfully tested and commissioned in Indus-2 front-end for undulator. At present, the beam viewer is operating under vacuum of 5 x 10-10 mbar in the Indus-2 undulator front-end

  1. Radiation emission at channeling of electrons in a strained layer Si1-xGex undulator crystal

    DEFF Research Database (Denmark)

    Backe, H.; Krambrich, D.; Lauth, W.; Andersen, Kristoffer; Hansen, John Lundsgaard; Uggerhøj, Ulrik Ingerslev

    2013-01-01

    Experiments have been performed at the Mainz Microtron MAMI to explore the radiation emission spectra from a crystalline undulator at electron beam energies of 270 and 855 MeV. The epitaxially grown graded composition strained layer Si1-xGex undulator had 4-period with a period length View the Ma...... emission from finite single arc elements, taking into account also coherence effects, suggest that evidence for a weak undulator effect has been observed for the first time for electrons.......Experiments have been performed at the Mainz Microtron MAMI to explore the radiation emission spectra from a crystalline undulator at electron beam energies of 270 and 855 MeV. The epitaxially grown graded composition strained layer Si1-xGex undulator had 4-period with a period length View the Math...

  2. Spatial variability of prodeltaic undulations on the Guadalfeo River prodelta: support to the genetic interpretation as hyperpycnal flow deposits

    Science.gov (United States)

    Lobo, F. J.; Goff, J. A.; Mendes, I.; Bárcenas, P.; Fernández-Salas, L. M.; Martín-Rosales, W.; Macías, J.; Díaz del Río, V.

    2015-12-01

    Two fields of prodeltaic undulations located off the Guadalfeo River were studied by integrating surficial (multibeam bathymetry, backscatter, sediment samples) and sub-surface (seismic profiles, sediment cores) data. Our main motivation was to analyze the along- and across-shelf variability of the seafloor undulations, in order to obtain useful insights into genetic mechanisms. A geostatistical analysis was performed, based on the determination of characteristic parameters and derived relationships. The undulations occur over a concave-upward surface which shows a seaward-decreasing slope. Most of the undulations are symmetrical to asymmetrically-oriented toward the coast. Two main fields are correlated with the present and previous river mouths. The western field, associated with the modern river mouth, is highly symmetrical, with the higher undulations in an axial position and diminishing the width/height relationship both laterally and downslope. In contrast, the eastern field, associated with an historic river mouth, shows lower-amplitude undulations, the width/height changes are less pronounced, and the undulations are more elongated. The two undulation fields exhibit subseafloor reflections that are subparallel to the seafloor, with peaks that migrate upslope upward in the stratigraphic column and which appear to correlate with coarse-grained layers. We support the contention that prodeltaic undulations off the Guadalfeo River should be regarded as sediment waves. Assuming a sediment-wave process, a strong normal-to-contour sediment flows with a riverine origin (e.g., hyperpycnal flows) may have been active during undulation generation. Both morphometric parameters of the river basin and estimations of sediment concentration during exceptional flood events are in agreement with an episodic activity of high freshwater discharges. Most of the geomorphic parameters and stratigraphic observations indicate a change of sediment supply conditions related to the

  3. Neuromuscular Responses to Short-Term Resistance Training With Traditional and Daily Undulating Periodization in Adolescent Elite Judoka.

    Science.gov (United States)

    Ullrich, Boris; Pelzer, Thiemo; Oliveira, Sergio; Pfeiffer, Mark

    2016-08-01

    Ullrich, B, Pelzer, T, Oliveira, S, and Pfeiffer, M. Neuromuscular responses to short-term resistance training with traditional and daily undulating periodization in adolescent elite judoka. J Strength Cond Res 30(8): 2083-2099, 2016-The influence of different periodization models on neuromuscular outcomes after short-term strength training periods has not been examined in adolescent athletes. Eleven elite judoka (age: 14.8 ± 0.6 years, height: 163.2 ± 7.5 cm, body mass: 57.3 ± 11.1 kg, 5 boys/6 girls, and strength training experience: 2.7 ± 1.1 years) performed two 4-week strength training mesocycles (each with 12 sessions) with either traditional (TP) or daily undulating (DUP) periodization. Both mesocycles were separated by a 7-week washout period and added to the regular judo training. Strength training was performed as lifting and lowering of weights using squats, knee flexion curl, clean & jerk, snatch, bench press, barbell bench pull, and lat pull-down. The mesocycles were equated for the number of repetitions and different intensity zones (50-90% of 1 repetition maximum [1RM]), addressing the optimization of strength, power, or velocity. Laboratory and 1RM testing was carried out 2 times during the baseline (T1 and T2), after the TP mesocycle (T3), after the washout period (T4), and after the DUP mesocycle (T5). Isometric knee extensor and knee flexor maximum voluntary contractive capacity (MVC), electromyographic-estimated neural drive of the quadriceps femoris, vastus lateralis (VL) muscle architecture, and 1RMs of all training exercises were measured. ANOVA revealed moderate (5.5-13.5%) but significant (p ≤ 0.05) temporal gains in knee extensor MVC, 1RMs, and VL architecture during both the mesocycles. Wilcoxon tests detected no significant differences for the percentage changes of any outcome between the mesocycles. For adolescent judoka, TP and DUP were equally adept in improving neuromuscular outcomes during short-term training periods. PMID

  4. Gliotransmission modulates baseline mechanical nociception

    Directory of Open Access Journals (Sweden)

    Foley Jeannine C

    2011-12-01

    Full Text Available Abstract Pain is a physiological and adaptive process which occurs to protect organisms from tissue damage and extended injury. Pain sensation beyond injury, however, is a pathological process which is poorly understood. Experimental models of neuropathic pain demonstrate that reactive astrocytes contribute to reduced nociceptive thresholds. Astrocytes release "gliotransmitters" such as D-serine, glutamate, and ATP, which is extracellularly hydrolyzed to adenosine. Adenosine 1 receptor activation in the spinal cord has anti-nociceptive effects on baseline pain threshold, but the source of the endogenous ligand (adenosine in the spinal cord is unknown. In this study we used a transgenic mouse model in which SNARE-mediated gliotransmission was selectively attenuated (called dnSNARE mice to investigate the role of astrocytes in mediating baseline nociception and the development of neuropathic pain. Under baseline conditions, immunostaining in the dorsal horn of the spinal cord showed astrocyte-specific transgene expression in dnSNARE mice, and no difference in expression levels of the astrocyte marker GFAP and the microglia marker Iba1 relative to wild-type mice. The Von Frey filament test was used to probe sensitivity to baseline mechanical pain thresholds and allodynia following the spared nerve injury model of neuropathic pain. DnSNARE mice exhibit a reduced nociceptive threshold in response to mechanical stimulation compared to wild-type mice under baseline conditions, but nociceptive thresholds following spared nerve injury were similar between dnSNARE and wild-types. This study is the first to provide evidence that gliotransmission contributes to basal mechanical nociception.

  5. RF undulator for compact X-ray SASE source of variable wavelength

    International Nuclear Information System (INIS)

    A room-temperature RF undulator, fed by Ka-band radiation and intended to produce ∼1 nm wavelength radiation using moderate energy electrons, is considered. The necessary electron bunches with energy 0.2-1 GeV could be produced by petawatt laser pulses injected into plasma bubbles.

  6. Progress on the superconducting undulator for ANKA and on the instrumentation for R and D

    International Nuclear Information System (INIS)

    Superconducting undulators show a larger magnetic field strength for the same gap and period length, as compared to permanent magnet devices, which allows to generate X-ray beams of higher brilliance and with harder spectrum. The worldwide first short period length superconducting undulator is in operation since 2005 at the synchrotron light source ANKA in Karlsruhe [1]. To further drive the development in this field a research and development program is being carried out. In this contribution we report on the last progress of the construction of a 1.5 m long superconducting undulator with a period length of 15 mm, planned to be installed in ANKA beginning 2010 to be the light source of the new beamline NANO for high resolution X-ray scattering. The key specifications of the system are an undulator parameter K higher than 2 (with a magnetic gap of 5 mm) and a phase error smaller than 3.5 degrees. Cryocoolers will keep the coils at 4.2 K for a beam heat load of 4 W. The ongoing R and D includes improvements in understanding of the magnetic field properties and of the beam heat load mechanisms. The tools and instruments under development to fulfill these tasks are also discussed.

  7. Final construction of the C.R.E.O.L. 8 millimeter period hybrid undulator

    Energy Technology Data Exchange (ETDEWEB)

    Tesch, P.; Gallagher, J.; Elias, L. [Center for Research and Education in Optics and Lasers, Orlando, FL (United States)

    1995-12-31

    The construction of an 8 millimeter period hybrid undulator for the C.R.E.O.L. high power far-infared free electron laser has just been completed. This FEL is expected to come on-line in the fall of 1995 and produce close to a kilowatt of continuous power at wavelengths of 225 - 800 microns. The undulator has extremely precise mechanical tolerances and high field uniformity allowing for high electron beam recovery rates. Almost complete beam recovery is required for DC operation at high currents. A novel method for measuring the magnetic properties of individual magnets and sorting the magnets to reduce magnetic field errors will be reported. The peak field and phase errors of the undulator without the pole pieces are reduced through a magnet ordering procedure. These errors are further reduced by inserting and tuning adjustable pole pieces. The reduction of field errors through these two techniques will be presented. An analysis of the final undulator errors and the results of measurements of the mechanical tolerances will be presented.

  8. Beam heat load measurements in the cold bore superconductive undulator in ANKA

    CERN Document Server

    Casalbuoni, S; Hagelstein, M; Zimmermann, F; Rossmanith, Robert; Kostka, Barbara; Mashkina, Elena; Steffens, Erhard; Bernhard, Axel; Wollmann, Daniel; Baumbach, Tilo

    2007-01-01

    Measurements of the beam-induced heat load in the ANKA cold-bore superconductive undulator are summarized. The strength of the two dominating effects, resistive wall heating and heating by electron bombardment, depends on the beam parameters and the gap width.

  9. Coherent undulator radiation of electron beam, microbunched for the FEL power outcoupling

    Energy Technology Data Exchange (ETDEWEB)

    Kulipanov, G.N.; Sokolov, A.S.; Vinokurov, N.A. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)

    1995-12-31

    The spectral intensity of the coherent undulator radiation of electron beam, preliminarily microbunched by the FEL oscillator for the FEL power outcoupling, is approximately calculated by simple analytic considerations, taking into account the transverse emittances and the energy spread of the microbunched electron beams.

  10. Modeling the formation of undulations of the coastline: the role of tides

    NARCIS (Netherlands)

    van der Vegt, M.; Schuttelaars, H.; de Swart, H.E.

    2007-01-01

    An idealized model is developed and analyzed to investigate the relevance of tidal motion for the emergence of undulations of a sandy coastline. The model describes feedbacks between tidal and steady flow on the inner shelf, sand transport in the nearshore zone and an irregular coastline. It is demo

  11. Performance of photon position monitors and stability of undulator beams at the Advanced Light Source

    International Nuclear Information System (INIS)

    Position monitors are implemented in three undulator beamlines at the ALS. Their performance has been studied carefully on one of these lines and is reviewed. The monitors work as expected and show the ALS to be an exceptionally stable source of synchrotron radiation

  12. Storage ring free electron laser. Operation with two undulators having opposite circular polarizations

    International Nuclear Information System (INIS)

    In Storage Ring Free Electron Lasers two undulators, having opposite helical polarizations and arranged as an Optical-Klystron, may be exploited to obtain linearly polarized radiation, without additional problems associated with mirror degradation, due to the higher on axis harmonic emission. In this paper it was explored the dynamical behavior of this device and discuss possible configurations allowing such as possibility

  13. Field fine tuning by pole height adjustment for the undulator of the TTF-FEL

    International Nuclear Information System (INIS)

    The field of the undulator for the VUV-FEL at the TESLA Test Facility has to meet very tough tolerances in order to guarantee a close overlap between the electron beam and the laser field. Consequently the undulator was designed to have height-adjustable poles in order to allow for fine tuning of the vertical undulator field in such a way that the trajectory is straightened. The signature of local pole height and gap changes on the field distribution was investigated. It was seen that changes are not restricted to the pole itself. Its effect can be seen up to the next eight neighboring poles. In this contribution we describe an algorithm in detail, which allows the prediction of required pole height changes in order to correct for field errors. As input data field errors deduced from precise magnetic field measurements are used together with the signatures of pole movements. A band diagonal system of linear equations has to be solved to obtain the pole height corrections. For demonstration of the method the field of the 0.9 m long prototype structure was optimized to have a straight trajectory. Since only a sparse band diagonal system of equations has to be solved, the method has the potential to be used in very long undulators having 600 -1000 poles

  14. A robotic device with a passive undulating ribbon fin: kinematics and propulsive performance

    Science.gov (United States)

    Liu, Hanlin; Curet, Oscar

    2015-11-01

    Many aquatic animals swim with high maneuverability using undulating ribbon fins. In this type of swimming, the organism propels by sending one or multiple traveling waves along an elongated fin. In previous work, robotic models with fully actuated fins where the parameters of the traveling waves are fully prescribed have been used to study the propulsive performance and fluid dynamics of this type of propulsion. However, less work has been done in ribbon fins with passively undulating waves. In this work, we use a robotic device to study the kinematics and propulsive performance of a passively undulating ribbon fin. The physical model is composed of fifteen rays interconnected with a membrane. Only two rays are actuated while the other rays are free to rotate through a common axis. The robotic fin was tested in a flume at different flow conditions. In a series of experiments we measured fin kinematics, propulsive forces and power consumption. As the leading two rays are actuated, a traveling wave with decaying amplitude passes through the passive rays. As the frequency of the actuated rays increases, the enclosed area of the undulating wave and the traveling wave frequency increase while the wavelength decreases. Our data also show that the propulsive force generated by the fin scaled with the enclosed area and the square of the relative velocity between incoming flow and traveling wave. These results suggest that both natural swimmers and underwater vehicles using ribbon-fin-based propulsion can potentially take advantage of passive undulating waves. National Science Foundation Grant No. 1420774

  15. Tuning and characterization of the {open_quotes}Teufel{close_quotes}-undulator

    Energy Technology Data Exchange (ETDEWEB)

    Verschuur, J.W.J.; Ernst, G.J.; Witteman, W.J. [Univ. of Twente, Enschede (Netherlands)

    1995-12-31

    Three important criteria are used to tune the undulator are: reduce longitudinal phase errors, have approximately equal two plane focusing and have a good overlap between the electron beam and the optical beam. Although these criteria are the main design goals it is hard to meet them directly from the assembling. Small errors inevitably appear during the assembly, even when care is taken to keep the tolerances as tight as possible. The magnetic field was constantly monitored during construction using the pulsed wire method. However some kind of tuning mechanism is always needed to improve the performance of the undulator. The undulator we designed and build is of the Hybrid type, i.e. permanent magnets and high permeable poles. The well known method of using small permanent magnets to correct the field errors is nearly impossible due to the presence of iron poles. Hence, as a logical step, we decided to try to correct the various errors with shims in the form of small iron plates. The shims were put on the pole face at the edge of the poles. Different configurations were used to correct the different kind of errors. In the presentation an overview of the various shim configurations will be discussed. Steering errors are quite easy to correct, since only dipole fields are involved. We did put quite some effort in correcting the quadrupole errors. Gradients dBy/dx and dBx/dy were easy to correct with two shims on one side. The other gradients, on the other hand needed extensive shimming to be corrected. The error correction is limited by the presence of sextupole errors. We even found by experience that sextupole errors increased with the number of shims used. The ratio of the focusing strength of the undulator is measured to be 3/2, being slightly stronger in the direction of the wiggle motion. Longitudinal phase errors are introduced by amplitude and wavelength deviations in the undulator.

  16. Tailoring the amplification of attosecond pulse through detuned X-ray FEL undulator.

    Science.gov (United States)

    Kumar, Sandeep; Kang, Heung-Sik; Kim, Dong Eon

    2015-02-01

    We demonstrate that the amplification of attosecond pulse in X-ray free electron laser (FEL) undulator can be tailored. The characteristic of the amplification of an isolated attosecond pulse in the FEL undulator is investigated. An isolated 180 attoseconds full width half maximum (FWHM) pulse at 1.25 nm with a spectral bandwidth of 1% is injected into an undulator. The simulation results show that for a direct seeding of 3MW, the seed is amplified to the peak power of 106 GW (40 μJ, an output pulse-width of 383 attoseconds) in the presence of a detuning at FEL resonance condition in 100-m long undulator. We note that the introduction of detuning leads to the better performance compared to the case without detuning: shorter by 15.5% in a pulse-width and higher by 76.6% in an output power. Tapering yields a higher power (116% increases in the output power compared to the case without detuning) but a longer pulse (15.4% longer in the pulse-width). It was observed that ± Δλ(r)/8 (Δλ(r)/λ(r) ~1%) is the maximum degree of detuning, beyond which the amplification becomes poor: lower in the output power and longer in the pulse duration. The minimum power for a seed pulse needs to be higher than 1 MW for the successful amplification of an attosecond pulse at 1.25 nm. Also, the electron beam energy-spread must be less than 0.1% for a suitable propagation of attosecond pulse along the FEL undulator under this study. PMID:25836141

  17. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    Energy Technology Data Exchange (ETDEWEB)

    Debus, Alexander

    2012-09-06

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  18. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    International Nuclear Information System (INIS)

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  19. Baseline budgeting for continuous improvement.

    Science.gov (United States)

    Kilty, G L

    1999-05-01

    This article is designed to introduce the techniques used to convert traditionally maintained department budgets to baseline budgets. This entails identifying key activities, evaluating for value-added, and implementing continuous improvement opportunities. Baseline Budgeting for Continuous Improvement was created as a result of a newly named company president's request to implement zero-based budgeting. The president was frustrated with the mind-set of the organization, namely, "Next year's budget should be 10 to 15 percent more than this year's spending." Zero-based budgeting was not the answer, but combining the principles of activity-based costing and the Just-in-Time philosophy of eliminating waste and continuous improvement did provide a solution to the problem. PMID:10387778

  20. The Nuts and Bolts of Baseline Setting

    OpenAIRE

    Partnership for Market Readiness

    2012-01-01

    This document provides an overview of baseline setting for greenhouse gas (GHG) crediting mechanisms. The first section briefly explains the general purpose and objectives of setting a crediting mechanism baseline. The second section summarizes key policy considerations in defining and setting baselines. The final section covers important technical elements of baselines and provides an ove...

  1. Time-resolved energy-dispersive diffraction from X-FEL spontaneous emission: a proposal for sub-picosecond pumps & probe structural investigations

    Science.gov (United States)

    Rossi Albertini, Valerio; Paci, Barbara; Perfetti, Paolo

    2004-11-01

    The forthcoming generation of X-ray machines, based on Free Electron Laser (X-FEL) technology, should provide ultra-short pulses that may be used to probe the real-time structural evolution of a system activated by an optical laser pump. Unfortunately, the sub-picosecond synchronization of the pump and probe pulses produced by two independent sources is, at present, one of the main obstacles that needs to be overcome. Here we propose a new approach for carrying out time-resolved diffraction studies of evolving systems, which aims to bypass the synchronization problem.

  2. Baseline LAW Glass Formulation Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Albert A. [USDOE Office of River Protection, Richland, WA (United States); Mooers, Cavin [The Catholic University of America, Washington, DC (United States). Vitreous State Lab.; Bazemore, Gina [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Pegg, Ian L. [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Hight, Kenneth [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Lai, Shan Tao [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Buechele, Andrew [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Rielley, Elizabeth [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Gan, Hao [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Muller, Isabelle S. [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Cecil, Richard [The Catholic University of America, Washington, DC (United States). Vitreous State Lab

    2013-06-13

    The major objective of the baseline glass formulation work was to develop and select glass formulations that are compliant with contractual and processing requirements for each of the LAW waste streams. Other objectives of the work included preparation and characterization of glasses with respect to the properties of interest, optimization of sulfate loading in the glasses, evaluation of ability to achieve waste loading limits, testing to demonstrate compatibility of glass melts with melter materials of construction, development of glass formulations to support ILAW qualification activities, and identification of glass formulation issues with respect to contract specifications and processing requirements.

  3. Environmental Baseline File National Transportation

    International Nuclear Information System (INIS)

    This Environmental Baseline File summarizes and consolidates information related to the national-level transportation of commercial spent nuclear fuel. Topics addressed include: shipments of commercial spent nuclear fuel based on mostly truck and mostly rail shipping scenarios; transportation routing for commercial spent nuclear fuel sites and DOE sites; radionuclide inventories for various shipping container capacities; transportation routing; populations along transportation routes; urbanized area population densities; the impacts of historical, reasonably foreseeable, and general transportation; state-level food transfer factors; Federal Guidance Report No. 11 and 12 radionuclide dose conversion factors; and national average atmospheric conditions

  4. Baseline report for infiltration experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aalto, P. (ed.); Helin, J.; Lindgren, S. (and others)

    2011-04-15

    An infiltration experiment to investigate potential changes in pH and redox conditions and in buffering capacity as well as the hydrogeochemical processes related to groundwater infiltration was started in late 2008 near ONKALO. The purpose of the experiment is to monitor the major infiltration flow path from ground surface into the upper part of ONKALO at a depth of about 50 to 100 m depending on the observations made during the experiment. Infiltration is activated by pumping a highly transmissive fracture zone (13-18.2 m) in drillhole OL-KR14, which is a part of the site scale hydrogeological feature. The influence of pumping is then monitored in drillholes, groundwater observation tubes and lysimeters through water, groundwater and microbiological samplings and hydrogeological measurements. Before the experiment was started, four new monitoring drillholes, nine groundwater observation tubes and nine lysimeters were installed in the test area and very detailed baseline field investigations were performed. In addition, information of existing investigation data from the area of interest was collected in together. The baseline field investigations included geological logging of the cores of new shallow drillholes, flow and transverse flow measurements in new shallow drillholes, SLUG measurements in groundwater observation tubes, head monitoring, groundwater and microbiological sampling and analysis from observation tubes, shallow drillholes and the pumping section in OL-KR14, water sampling and analysis from lysimeters and resistivity measurements of the overburden. The results of previously performed soil pit investigations and hydrogeological measurements carried out in the area of interest were also added to the investigation data. A detailed hydrogeological model of the experiment area was updated simultaneously with baseline field investigations; the previous version was presented in Pitkaenen et al. (2008). Apart from the field investigations, predictive

  5. Long-Baseline Neutrino Experiments

    CERN Document Server

    Diwan, M V; Qian, X; Rubbia, A

    2016-01-01

    We review long-baseline neutrino experiments in which neutrinos are detected after traversing macroscopic distances. Over such distances neutrinos have been found to oscillate among flavor states. Experiments with solar, atmospheric, reactor, and accelerator neutrinos have resulted in a coherent picture of neutrino masses and mixing of the three known flavor states. We will summarize the current best knowledge of neutrino parameters and phenomenology with our focus on the evolution of the experimental technique. We proceed from the first evidence produced by astrophysical neutrino sources to the current open questions and the goals of future research.

  6. Baseline report for infiltration experiment

    International Nuclear Information System (INIS)

    An infiltration experiment to investigate potential changes in pH and redox conditions and in buffering capacity as well as the hydrogeochemical processes related to groundwater infiltration was started in late 2008 near ONKALO. The purpose of the experiment is to monitor the major infiltration flow path from ground surface into the upper part of ONKALO at a depth of about 50 to 100 m depending on the observations made during the experiment. Infiltration is activated by pumping a highly transmissive fracture zone (13-18.2 m) in drillhole OL-KR14, which is a part of the site scale hydrogeological feature. The influence of pumping is then monitored in drillholes, groundwater observation tubes and lysimeters through water, groundwater and microbiological samplings and hydrogeological measurements. Before the experiment was started, four new monitoring drillholes, nine groundwater observation tubes and nine lysimeters were installed in the test area and very detailed baseline field investigations were performed. In addition, information of existing investigation data from the area of interest was collected in together. The baseline field investigations included geological logging of the cores of new shallow drillholes, flow and transverse flow measurements in new shallow drillholes, SLUG measurements in groundwater observation tubes, head monitoring, groundwater and microbiological sampling and analysis from observation tubes, shallow drillholes and the pumping section in OL-KR14, water sampling and analysis from lysimeters and resistivity measurements of the overburden. The results of previously performed soil pit investigations and hydrogeological measurements carried out in the area of interest were also added to the investigation data. A detailed hydrogeological model of the experiment area was updated simultaneously with baseline field investigations; the previous version was presented in Pitkaenen et al. (2008). Apart from the field investigations, predictive

  7. FED baseline engineering studies report

    Energy Technology Data Exchange (ETDEWEB)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept.

  8. FED baseline engineering studies report

    International Nuclear Information System (INIS)

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept

  9. A Design Report of the Baseline for PEP-X: an Ultra-Low Emittance Storage Ring

    Energy Technology Data Exchange (ETDEWEB)

    Bane, Karl; Bertsche, Kirk; Cai, Yunhai; Chao, Alex; Corbett, Willian; Fox, John; Hettel, Robert; Huang, Xiaobiao; Huang, Zhirong; Ng, Cho-Kuen; Nosochkov, Yuri; Novokhatski, Sasha; Radedeau, Thomas; Raubenheimer, Tor; Rivetta, Claudio; Safranek, James; Seeman, John; Stohr, Joachim; Stupakov, Gennady; Wang, Lanfa; Wang, Min-Huey; /SLAC

    2010-06-02

    Over the past year, we have worked out a baseline design for PEP-X, as an ultra-low emittance storage ring that could reside in the existing 2.2-km PEPII tunnel. The design features a hybrid lattice with double bend achromat (DBA) cells in two arcs and theoretical minimum emittance (TME) cells in the remaining four arcs. Damping wigglers are used to reduce the horizontal emittance to 86 pm-rad at zero current for a 4.5 GeV electron beam. At a design current of 1.5 A, the horizontal emittance increases, due to intrabeam scattering, to 164 pm-rad when the vertical emittance is maintained at a diffraction limited 8 pm-rad. The baseline design will produce photon beams achieving a brightness of 10{sup 22} (ph/s/mm{sup 2}/mrad{sup 2}/0.1% BW) at 10 keV in a 3.5-m conventional planar undulator. Our study shows that an optimized lattice has adequate dynamic aperture, while accommodating a conventional off-axis injection system. In this report, we present the results of study, including the lattice properties, nonlinear dynamics, intra-beam scattering and Touschek lifetime, RF system, and collective instabilities. Finally, we discuss the possibility of partial lasing at soft X-ray wavelengths using a long undulator in a straight section.

  10. Ice Velocity Mapping of Ross Ice Shelf, Antarctica by Matching Surface Undulations Measured by Icesat Laser Altimetry

    Science.gov (United States)

    Lee, Choon-Ki; Han, Shin-Chan; Yu, Jaehyung; Scambos, Ted A.; Seo, Ki-Weon

    2012-01-01

    We present a novel method for estimating the surface horizontal velocity on ice shelves using laser altimetrydata from the Ice Cloud and land Elevation Satellite (ICESat; 20032009). The method matches undulations measured at crossover points between successive campaigns.

  11. X-ray radiation damage studies and design of a silicon pixel sensor for science at the XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiaguo

    2013-06-15

    Experiments at the European X-ray Free Electron Laser (XFEL) require silicon pixel sensors which can withstand X-ray doses up to 1 GGy. For the investigation of Xray radiation damage up to these high doses, MOS capacitors and gate-controlled diodes built on high resistivity n-doped silicon with crystal orientations left angle 100 right angle and left angle 111 right angle produced by four vendors, CiS, Hamamatsu, Canberra and Sintef have been irradiated with 12 keV X-rays at the DESY DORIS III synchrotron-light source. Using capacitance/ conductance-voltage, current-voltage and thermal dielectric relaxation current measurements, the densities of oxide charges and interface traps at the Si-SiO{sub 2} interface, and the surface-current densities have been determined as function of dose. Results indicate that the dose dependence of the oxide-charge density, the interface-trap density and the surface-current density depend on the crystal orientation and producer. In addition, the influence of the voltage applied to the gates of the MOS capacitor and the gate-controlled diode during X-ray irradiation on the oxide-charge density, the interface-trap density and the surface-current density has been investigated at doses of 100 kGy and 100 MGy. It is found that both strongly depend on the gate voltage if the electric field in the oxide points from the surface of the SiO{sub 2} to the Si-SiO{sub 2} interface. To verify the long-term stability of irradiated silicon sensors, annealing studies have been performed at 60 C and 80 C on MOS capacitors and gate-controlled diodes irradiated to 5 MGy as well, and the annealing kinetics of oxide charges and surface current were determined. Moreover, the macroscopic electrical properties of segmented sensors have slao been investigated as function of dose. It is found that the defects introduced by X-rays increase the full depletion voltage, the surface leakage current and the inter-electrode capacitance of the segmented sensor. An

  12. X-ray radiation damage studies and design of a silicon pixel sensor for science at the XFEL

    International Nuclear Information System (INIS)

    Experiments at the European X-ray Free Electron Laser (XFEL) require silicon pixel sensors which can withstand X-ray doses up to 1 GGy. For the investigation of Xray radiation damage up to these high doses, MOS capacitors and gate-controlled diodes built on high resistivity n-doped silicon with crystal orientations left angle 100 right angle and left angle 111 right angle produced by four vendors, CiS, Hamamatsu, Canberra and Sintef have been irradiated with 12 keV X-rays at the DESY DORIS III synchrotron-light source. Using capacitance/ conductance-voltage, current-voltage and thermal dielectric relaxation current measurements, the densities of oxide charges and interface traps at the Si-SiO2 interface, and the surface-current densities have been determined as function of dose. Results indicate that the dose dependence of the oxide-charge density, the interface-trap density and the surface-current density depend on the crystal orientation and producer. In addition, the influence of the voltage applied to the gates of the MOS capacitor and the gate-controlled diode during X-ray irradiation on the oxide-charge density, the interface-trap density and the surface-current density has been investigated at doses of 100 kGy and 100 MGy. It is found that both strongly depend on the gate voltage if the electric field in the oxide points from the surface of the SiO2 to the Si-SiO2 interface. To verify the long-term stability of irradiated silicon sensors, annealing studies have been performed at 60 C and 80 C on MOS capacitors and gate-controlled diodes irradiated to 5 MGy as well, and the annealing kinetics of oxide charges and surface current were determined. Moreover, the macroscopic electrical properties of segmented sensors have slao been investigated as function of dose. It is found that the defects introduced by X-rays increase the full depletion voltage, the surface leakage current and the inter-electrode capacitance of the segmented sensor. An electron

  13. Beam dynamics studies during commissioning of two undulators in Indus-2

    International Nuclear Information System (INIS)

    Indus-2, a synchrotron light source facility at RRCAT, Indore is in continuous operation at 2.5 GeV, generating the synchrotron radiation from its bending magnets. For enhancing the intensity of synchrotron radiation, two planar undulators have been installed and successfully commissioned with the Indus-2 electron beam. Various beam dynamical challenges such as beam accumulation, beam energy ramping and storage at 2.5 GeV have been addressed to ensure the smooth commissioning of these devices. Moreover, due to interaction of the stored beam with magnetic field of undulators, various parameters of the electron beam get changed. In this paper, the beam dynamics studies to ensure the smooth commissioning of these devices and its measured effect on beam parameters have been presented. (author)

  14. A hybrid type undulator for far-infrared FELs at FELI

    Energy Technology Data Exchange (ETDEWEB)

    Zako, A.; Miyauchi, Y.; Koga, A. [Free Electron Laser Research Institute, Inc., Osaka (Japan)] [and others

    1995-12-31

    Two FEL facilities of the FELI are now operating in the wavelength range of 1-20 {mu}m. A 3.2-m hybrid type undulator ({lambda}{sub u}=80mm, N=40) has been designed for far-infrared FELs and will be installed in December. It can cover the wavelength of 20-60 {mu}m by changing K-value from 1 to 2.7 for a 28.0-MeV electron beam. It is composed of ferrite magnetic poles and Sm-Co permanent magnets. Commonly wound coils induce alternating magnetic field in ferrite poles. Combination of the induced field and the permanent magnet field can controls the magnetic field between the undulator gap.

  15. Analysis of pulsed wire method for field integral measurements in undulators

    Indian Academy of Sciences (India)

    Vinit Kumar; Ganeshwar Mishra

    2010-05-01

    Pulsed wire technique is a fast and accurate method for the measurement of first and second field integrals of undulators used in free-electron lasers and synchrotron light sources. In this paper, we present a theoretical analysis of this technique by finding out the analytic solution of the differential equation for the forced vibration of the wire taking dispersion due to stiffness into account. Method of images is used to extend these solutions to include reflections at the ends. For long undulators, the effect of dispersion of the acoustic wave in the wire could be significant and our analysis provides a method for the evaluation of the magnetic field profile even in such cases taking the effect due to dispersion into account in an exact way.

  16. Tapering studies for Terawatt level X-ray FELs with a superconducting undulator

    CERN Document Server

    Emma, Claudio; Emma, Paul; Huang, Zhirong; Pellegrini, Claudio

    2015-01-01

    We study the tapering optimization scheme for a short period, less than two cm, superconducting undulator, and show that it can generate 4 keV X-ray pulses with peak power in excess of 1 terawatt, using LCLS electron beam parameters. We study the e?ect of undulator module length relative to the FEL gain length for continous and step-wise taper pro?les. For the optimal section length of 1.5m we study the evolution of the FEL process for two di?erent superconducting technologies NbTi and Nb3Sn. We discuss the major factors limiting the maximum output power, particle detrapping around the saturation location and time dependent detrapping due to generation and ampli?cation of sideband modes.

  17. Impact of undulator wake-fields and tapering on the European X-ray FEL performance

    International Nuclear Information System (INIS)

    In this paper we estimate the induced wakefields in an elliptical pipe geometry taking into account main geometrical variations of the chamber. To study the expected performance in the presence of the calculated wakefields we are doing start-to-end simulations with the codes ASTRA, CSRtrack and Genesis. In order to compensate the impact of wake fields on the FEL performance, an adiabatic change of undulator parameters is applied. (orig.)

  18. A Study on Inviscid Flow with a Free Surface over an Undulating Bottom

    OpenAIRE

    Srikumar Panda

    2016-01-01

    In this paper, the problem involving inviscid flow with a free surface over an undulating bottom is studied within the framework of linear theory. Applying perturbation analysis in conjunction with the Fourier transform technique, the boundary value problem arising from the flow problem is solved analytically. Behaviour of both interface and free-surface profiles, which are unknown at the outset, are analyzed. It is found that each profile (interface and free-surface) possesses a ...

  19. On simulating lipid bilayers with an applied surface tension: periodic boundary conditions and undulations.

    OpenAIRE

    Feller, S E; Pastor, R W

    1996-01-01

    As sketched in Fig. 1, a current molecular dynamics computer simulation of a lipid bilayer fails to capture significant features of the macroscopic system, including long wavelength undulations. Such fluctuations are intrinsically connected to the value of the macroscopic (or thermodynamic) surface tension (cf. Eqs. 1 and 9; for a related treatment, see Brochard et al., 1975, 1976). Consequently, the surface tension that might be evaluated in an MD simulation should not be expected to equal t...

  20. Undulative induction electron accelerator for the waste and natural water purification systems

    CERN Document Server

    Kulish, Victor V; Gubanov, I V

    2001-01-01

    The project analysis of Undulative Induction Accelerator (EH - accelerator) for the waste and natural water purification systems is accomplished. It is shown that the use of the four-channel design of induction block and the standard set of auxiliary equipment (developed earlier for the Linear Induction Accelerators - LINACs) allow to construct commercially promising purification systems. A quality analysis of the accelerator is done and the optimal parameters are chosen taking into account the specific sphere of its usage.

  1. Spectral character of optimized undulator insertion devices for the synchrotron x-ray source at Argonne

    International Nuclear Information System (INIS)

    Two general types of undulator x-ray sources are planned for the Advanced Photon Source (APS) to be built at Argonne. One is to provide first harmonic radiation tunable over the interval of 7 to 14 keV during the initial phase of operation of the storage ring. This tunability range will increase for the same device to approximately 4.7 to 14 keV during the mature phase of operation. The larger tunability interval corresponds to a smaller vertical stay free clearance expected for the final operating conditions of the ring. This allows for a smaller undulator magnetic gap and hence lower energy first harmonic radiation. By using the higher harmonics of this device, considerable intensity will be available at 20 keV and above. A second device with a smaller period is planned for those cases where the intensity of the third harmonic radiation from the above device is not sufficient. In this case, the undulator will provide 20 keV radiation in the first harmonic. The magnetic design of both devices will be a hybrid type which uses the Nd-Fe-B alloy as the permanent magnet material and vanadium permendur as the pole-tip. As part of the optimization scheme, the magnetic field calculations have been carried out using a version of the two dimensional field code PANDIRA. In this approximation, the width of the undulator is assumed to be infinite. Three dimensional effects associated to finite pole widths have been estimated using experimental results of single pole measurements for a 7 cm period device. In addition, numerical calculations of the spectral characteristics have been done using the magnetic design parameters and taking into account the emittance expected for the APS. On-axis brilliance results as well as expected spectral power densities have been determined

  2. Beamline 9.0.1 - a high-resolution undulator beamline for gas-phase spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bozek, J.D.; Heimann, P.A.; Mossessian, D. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    Beamline 9.0.1 at the Advanced Light Source is an undulator beamline with a Spherical Grating Monochromator (SGM) which provides very high resolution and flux over the photon energy range 20-320eV. The beamline has been used primarily by the atomic and molecular science community to conduct spectroscopy experiments using electron, ion and fluorescence photon detection. A description of the beamline and its performance will be provided in this abstract.

  3. A rapidly-modulated variable-polarization crossed-undulator source

    International Nuclear Information System (INIS)

    Within the areas of chemistry, life sciences, materials science, and physics, there is a growing interest in experiments which require an intense source of variably-polarized photons and which can be modulated between variable polarization states at frequencies up to 10 Hz. This interest is also being anticipated by 3rd generation sources which will become operational in the next few years. Therefore, a collaboration of scientists at ANL, LBL, and SRC is designing such a source at the Aladdin storage ring, SRC. The source consists of two orthogonal undulators, separated longitudinally by a modulator which varies the path length of the electrons passing through, and hence, effectively the phasing of the radiation from each of the two undulators. Varying the longitudinal spacing of the undulators permits any base polarization state, linear, elliptical, or circular. Further, the modulator can rapidly vary the phasing between undulators by up to 90 degree, permitting variations between circular polarization of opposite handedness, or orthogonal linear states. The source will provide radiation tunable over the range from 8-40 eV. Besides the source, an initial-phase beam line is planned. This beam line includes diagnostics which can be used to characterize and control the polarization state of the radiation. This facility would be immediately useful to research teams at SRC. Furthermore, it would provide valuable experience for the implementation of such devices at 3rd generation sources such as ALS and APS. This paper presents design work to date on this entire project. Topics covered will be; the rationale for the configuration; parameter selection based on the requirements of both the users and stable operation on the Aladdin storage ring; and, the requirements and conceptual design for a most critical component - the magnetic modulator

  4. Effects of Elliptically Polarizing Undulator on Beam Dynamics in PLS-II

    CERN Document Server

    Shin, S; Huang, J-Y

    2016-01-01

    The non-linear effects caused by the intrinsic field transverse roll-off in an Elliptically Polarizing Undulator with 72-mm period and maximum peak field of 0.72 T (EPU72) on the dynamics aperture of the Pohang Light Source II (PLS-II) were investigated. A kick map and Frequency map analysis both demonstrated that EPU72 will not reduce the lifetime or cause injection problems in PLS-II.

  5. Undulative induction electron accelerator for the waste and natural water purification systems

    International Nuclear Information System (INIS)

    The project analysis of Undulative Induction Accelerator (EH - accelerator) for the waste and natural water purification systems is accomplished. It is shown that the use of the four-channel design of induction block and the standard set of auxiliary equipment (developed earlier for the Linear Induction Accelerators - LINACs) allow to construct commercially promising purification systems. A quality analysis of the accelerator is done and the optimal parameters are chosen taking into account the specific sphere of its usage

  6. Effects of undulators on the ALS: The early work on the LBL [Lawrence Berkeley Laboratory

    International Nuclear Information System (INIS)

    In this paper we describe the early work carried out at LBL on the consequences of installing insertion devices (wigglers and undulators) on the beam dynamics of the ALS. This included analytical and tracking studies, and led to an insight to the reasons behind the predicted reduction in dynamic aperture. For completeness, a description of the unperturbed storage ring characteristics are also given. 3 refs., 16 figs., 2 tabs

  7. Magnetic field measurements of the harmonic generation FEL superconducting undulator at BNL-NSLS

    International Nuclear Information System (INIS)

    A three stage superconducting undulator (modulator, dispersive section, and radiator) is under construction at Brookhaven National Laboratory. Sections of the radiator, consisting of 25cm long steel yokes, each with 18mm period, 0.54 Tesla field, and 8.6mm gap are under test. The magnetic measurements and operational characteristics of the magnet are discussed. Measurement results and analysis are presented, with emphasis on the integrated field quality. The magnet winding and the effects of the various trims are discussed

  8. Chamber Surface Roughness and Electron Cloud for the Advanced Photon Source Superconducting Undulator

    OpenAIRE

    Boon, Laura; Harkay, Katherine

    2013-01-01

    The electron cloud is a possible heat source in the superconducting undulator (SCU) designed for the Advanced Photon Source (APS), a 7-GeV electron synchrotron radiation source at Argonne National Laboratory. In electron cloud generation extensive research has been done, and is continuing, to understand the secondary electron component. However, little work has been done to understand the parameters of photoemission in the accelerator environment. To better understand the primary electron gen...

  9. Image tuning techniques for enhancing the performance of pure permanent magnet undulators with small gap/period ratios

    Energy Technology Data Exchange (ETDEWEB)

    Tatchyn, R. [Stanford Univ., CA (United States)

    1995-12-31

    The on-axis field of a small-gap undulator constricted out of pure permanent magnet (PM) blocks arranged in an alternating-dipole (i.e., 2 dipoles/period) array can be substantially varied by positioning monolithic permeable plates above and below the undulator jaws. This simple technique, which can be used to control the 1st harmonic energy in conventional synchrotron radiation (SR) or Free Electron Laser (FEL) applications requiring sub-octave tuning, can also be shown to suppress magnetic inhomogeneities that can contribute to the undulator`s on-axis field errors. If a standard 4 block/period Halbach undulator, composed of PM blocks with square cross sections, is rearranged into an alternating-dipole array with the same period, the peak field that can be generated with superimposed image plates can substantially exceed that of the pure-PM Halbach array. This design technique, which can be viewed as intermediate between the {open_quotes}pure-PM{close_quotes} and standard {open_quotes}hybrid/PM{close_quotes} configurations, provides a potentially cost-effective method of enhancing the performance of small-gap, pure-PM insertion devices. In this paper we report on the analysis and recent characterization of pure-PM undulator structures with superimposed image plates, and discuss possible applications to FEL research.

  10. Proposed Laser-driven, Dielectric Microstructure Few-cm Long Undulator for Attosecond Coherent X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Plettner, T; Byer, R.L.; /Stanford U., Ginzton Lab.

    2011-09-16

    This article presents the concept of an all-dielectric laser-driven undulator for the generation of coherent X-rays. The proposed laser-driven undulator is expected to produce internal deflection forces equivalent to a several-Tesla magnetic field acting on a speed-of-light particle. The key idea for this laser-driven undulator is its ability to provide phase synchronicity between the deflection force and the electron beam for a distance that is much greater than the laser wavelength. The potential advantage of this undulator is illustrated with a possible design example that assumes a small laser accelerator which delivers a 2 GeV, 1 pC, 1 kHz electron bunch train to a 10 cm long, 1/2 mm period laser-driven undulator. Such an undulator could produce coherent X-ray pulses with {approx}10{sup 9} photons of 64 keV energy. The numerical modeling for the expected X-ray pulse shape was performed with GENESIS, which predicts X-ray pulse durations in the few-attosecond range. Possible applications for nonlinear electromagnetic effects from these X-ray pulses are briefly discussed.

  11. Control software of a variably polarizing undulator (APPLE type) for SX beamline in the SPring-8

    Energy Technology Data Exchange (ETDEWEB)

    Hiramatsu, Yoichi [Kansai Research Establishment, Japan Atomic Energy Research Institute, Mikazuki, Hyogo (Japan); Shimada, Taihei; Miyahara, Yoshikazu

    1999-12-01

    This paper describes the control software of a variably polarizing undulator (APPLE Type) that was installed at the SX beamline (cell number 23) in the SPring-8 storage ring in February, 1998. This undulator produces a polarized radiation in the energy range of soft X-ray by changing the gap distance between two pairs of permanent magnet arrays (gap movement). The main characteristic of the undulator is a capability to generate right and left circular polarization alternately at a period of 2 sec (0.5 Hz) by high speed phase-shifting (periodic phase movement). The developed software makes a fast correction of the closed orbit distortion (COD) of an electron beam by exciting steering magnets at a rate of time interval of 24 msec (42 Hz) during the movement of magnet arrays. Also, the software is capable to put these magnet arrays into a constant periodic phase movement with an error less than 0.1% for the period of 2 sec. The software was developed in accordance with the directions of SPring-8 standard for software development. (author)

  12. Development of thin hall probes for field measurement of SACLA in-vacuum undulators

    International Nuclear Information System (INIS)

    In SACLA, the minimum gap of the undulator is planned to be narrowed from 3.5 mm to 2.5 mm in order to upgrade the laser performance. It is expected that the laser pulse energy is enhanced and the wavelength tunability is expanded without changing the electron beam energy. In order to close the gap less than 2.5 mm in the near future for further upgrade, it is required to miniaturize the hall probe. For this reason, a one-dimensional thin hall probe with the thickness of 0.5 mm was developed. Using this probe, the magnetic field of the in-vacuum undulator for SACLA was measured at the gap below 4.0 mm. The standard deviation of the phase error estimated with the measured field distribution at the gap of 4.0 mm was found to be 5.4 degrees which is close to 5.7 degrees estimated with the standard hall probe currently used for the undulator field measurement at SPring-8. Although this result shows that the developed hall probe reproduces the measurement with the existing probe, we have found that the reproducibility was not perfect at the gap of 3.5 mm. The reason for this discrepancy may possibly be attributable to that the hall-voltage offset was not adequately compensated. (author)

  13. Performance of an undulator for visible and UV FELs at FELI

    Energy Technology Data Exchange (ETDEWEB)

    Miyauchi, Y.; Zako, A.; Koga, A. [Free Electron Laser Research Institute, Inc., Osaka (Japan)] [and others

    1995-12-31

    Two infrared free electron lasers (FELs) of the FELI project are now operating in the wavelength range of 1-20{mu}m. A 2.68-m undulator has been constructed for visible and UV FELs covering the wavelength of 1-0.2{mu}m for 100-165 MeV electron beams. It generates alternating, horizontal magnetic field, and wiggles electron beam on a vertical plane. The undulator length and period are 2.68m and 40mm, respectively. The gap of undulator magnets can be changed remotely by using servomotors with an accuracy of 1 {mu}m from the control room. The maximum K-value and related magnetic field strength are 1.9 and 0.5T, respectively, when its gap is set to the minimum value of 16mm. In order to minimize magnetic field reduction due to radiation damage, Sm-Co permanent magnet was adopted. Its structure and the results of magnetic field measurement will be reported.

  14. Initial studies of Bremsstrahlung energy deposition in small-bore superconducting undulator structures in linac environments

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, T.; Tatchyn, R. [Stanford Univ., CA (United States)

    1995-12-31

    One of the more promising technologies for developing minimal-length insertion devices for linac-driven, single-pass Free Electron Lasers (FELs) operating in the x-ray range is based on the use of superconducting (SC) materials. In recent FEL simulations, for example, a bifilar helical SC device with a 2 cm period and 1.8 T field was found to require a 30 m saturation length for operation at 1.5{Angstrom} on a 15 GeV linac, more than 40% shorter than an alternative hybrid/permanent magnet (hybrid/PM) undulator. AT the same time, however, SC technology is known to present characteristic difficulties for insertion device design, both in engineering detail and in operation. Perhaps the most critical problem, as observed, e.g., by Madey and co-workers in their initial FEL experiments, was the frequent quenching induced by scattered electrons upstream of their (bifilar) device. Postulating that this quenching was precipitated by directly-scattered or bremsstrahlung-induced particle energy deposited into the SC material or into material contiguous with it, the importance of numerical and experimental characterizations of this phenomenon for linac-based, user-facility SC undulator design becomes evident. In this paper we discuss selected prior experimental results and report on initial EGS4 code studies of scattered and bremsstrahlung induced particle energy deposition into SC structures with geometries comparable to a small-bore bifilar helical undulator.

  15. The construction of a 9-pole prototype for SRRC U-10 undulator

    International Nuclear Information System (INIS)

    A 9-pole undulator prototype with a magnetic period length of 10 cm was designed and constructed to examine the mechanical and magnetic field performance. The hybrid permanent magnet structure was optimized by using 2D PANDIRA and 3D TOSCA magnetostatic codes. A half period magnet model was also fabricated to verify the magnetic field strength on-axis and the transverse field roll-off within 0.1% in the good field region of ±10 mm at a minimum gap of 22 mm. The end pole configurations, as equipped with either two tunable permanent magnetic rotators or steering coil correctors were designed for minimizing the deviation of the magnetic field strength integrals. The magnet structures were mounted on a 2 meter long C-frame support structure in which the gap could be moved in parallel and phase motion. The field characteristics and measurement results between the adjustable gap undulator (AGU) and the hybrid adjustable phase undulator (APU) were also presented

  16. Undulator superradiance effect and its applicability for the generation of multimegawatt terahertz pulses

    Science.gov (United States)

    Ginzburg, N. S.; Golovanov, A. A.; Zotova, I. V.; Malkin, A. M.; Tarakanov, V. P.

    2014-10-01

    The generation of multimegawatt terahertz pulses based on the superradiance of picosecond electron bunches moving in a periodic magnetic (undulator) field is shown to be possible. The theoretical study of superradiance processes is based both on the method of an averaged ponderomotive force and on direct numerical PIC (particle in cell) simulations. The analysis is performed in the K' reference frame comoving with the electrons followed by the recalculation of radiation characteristics to the laboratory frame using the Lorentz transformations. Within the framework of the averaged approach, the electron bunch is represented as an ensemble of macroelectrons interacting between themselves through the radiation fields and Coulomb forces. The superradiance effect includes particle bunching followed by coherent emission of a single intense pulse from the entire volume of an electron bunch whose length exceeds considerably the wavelength. PIC simulations of this process based on the KARAT code have been performed for a more detailed analysis including the transverse inhomogeneity of the undulator field, the relativistic pattern of electron motion in this field, etc. A considerable simplification of the calculation procedure when passing to the comoving reference frame due to the commensurability of all spatial scales, including the radiation wavelength, the bunch length, and the length of the train of the pump wave into which the undulator field is transformed, is shown to be possible.

  17. An elliptically-polarizing undulator with phase adjustable energy and polarization

    International Nuclear Information System (INIS)

    The authors present a planar helical undulator designed to produce elliptically polarized light. Helical magnetic fields may be produced by a variety of undulators with four parallel cassettes of magnets. In their design, all cassettes are mounted in two planes on slides so that they may be moved parallel to the electron beam. This allows the undulator to produce x-rays of left- or right-handed elliptical or circular polarization as well as horizontal or vertical linear polarization. In model calculations, they have found that by sliding the top pair of rows with respect to the bottom pair, or the left pair with respect to the right pair, they retain the polarization setting but change the magnetic field strength, and hence the x-ray energy. This allows them to select both energy and polarization by independent phase adjustments alone, without changing the gap between the rows. Such a design may be simpler to construct than an adjustable gap machine. The authors present calculations that model its operation and its effects on an electron beam

  18. Negative-mass mitigation of Coulomb repulsion for terahertz undulator radiation of electron bunches

    Energy Technology Data Exchange (ETDEWEB)

    Balal, N.; Magory, E. [Ariel University, Ariel 40700 (Israel); Bandurkin, I. V. [Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation); Bratman, V. L. [Ariel University, Ariel 40700 (Israel); Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation); Savilov, A. V. [Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, Nizhny Novgorod 603950 (Russian Federation)

    2015-10-19

    It is proposed to utilize the effect of negative mass for stabilization of the effective axial size of very dense and short electron bunches produced by photo-injector guns by using combined undulator and strong uniform magnetic fields. It has been shown that in the “abnormal” regime, an increase in the electron energy leads to a decrease in the axial velocity of the electron; due to the negative-mass effect, the Coulomb repulsion of electrons leads to their attraction and formation of a fairly stable and compact bunch “nucleus.” An undulator with a strong uniform magnetic field providing the negative-mass effect is designed for an experimental source of terahertz radiation. The use of the negative-mass regime in this experiment should result in a long-pulse coherent spontaneous undulator emission from a short dense moderately relativistic (5.5 MeV) photo-injector electron bunch with a high (up to 20%) efficiency and a narrow frequency spectrum.

  19. Negative-mass mitigation of Coulomb repulsion for terahertz undulator radiation of electron bunches

    International Nuclear Information System (INIS)

    It is proposed to utilize the effect of negative mass for stabilization of the effective axial size of very dense and short electron bunches produced by photo-injector guns by using combined undulator and strong uniform magnetic fields. It has been shown that in the “abnormal” regime, an increase in the electron energy leads to a decrease in the axial velocity of the electron; due to the negative-mass effect, the Coulomb repulsion of electrons leads to their attraction and formation of a fairly stable and compact bunch “nucleus.” An undulator with a strong uniform magnetic field providing the negative-mass effect is designed for an experimental source of terahertz radiation. The use of the negative-mass regime in this experiment should result in a long-pulse coherent spontaneous undulator emission from a short dense moderately relativistic (5.5 MeV) photo-injector electron bunch with a high (up to 20%) efficiency and a narrow frequency spectrum

  20. Design of a transmission grating hard X-ray spectrometer for laser-driven undulator sources

    Energy Technology Data Exchange (ETDEWEB)

    Werle, Christian; Maier, Andreas; Zeitler, Benno; Delbos, Niels; Gruener, Florian [University of Hamburg - CFEL, Hamburg (Germany); Kajumba, Nathaniel [Ludwig Maximilian Univ., Muenchen (Germany)

    2013-07-01

    State-of-the-art laser-driven undulator sources are already becoming very versatile and powerful light sources, especially due to their wavelength tunability and ultra-short pulses. However, being still in development, they suffer from instabilities, which can make the spectral characterization of their radiation rather challenging, especially in the few-nm range. The hard X-ray transmission grating spectrometer, presented in this talk, was specifically optimized to tackle these difficulties. Its simple base design and its fully motorized optical components grant a high degree of flexibility during operation, fitting nicely to the nature of this radiation source. During calibration the device has been proven to measure wavelengths from 18 nm to 5 nm, but was in general also designed to address the sub-nm range. Following these test runs, the spectrometer was installed during a undulator campaign and was successfully used to measure laser-driven undulator radiation from 100 eV up to 300 eV, being the highest energy photons ever demonstrated with such a source.

  1. Computational Study on a Squid-Like Underwater Robot with Two Undulating Side Fins

    Institute of Scientific and Technical Information of China (English)

    Md. Mahbubar Rahman; Yasuyuki Toda; Hiroshi Miki

    2011-01-01

    The undulating fin propulsion system is an instance of the bio-inspired propulsion systems. In the current study, the swimming motion of a squid-like robot with two undulating side fins, mimicking those of a Stingray or a Cuttlefish, was investigated through flow computation around the body. We used the finite analytic method for space discretization and Euler implicit scheme for time discretization along with the PISO algorithm for velocity pressure coupling. A body-fitted moving grid was generated using the Poisson equation at each time step. Based on the computed results, we discussed the features of the flow field and hydrodynamic forces acting on the body and fin. A simple relationship among the fin's principal dimensions was established. Numerical computation was done for various aspect ratios, fin angles and frequencies in order to validate the proposed relationship among principal dimensions. Subsequently, the relationship was examined base on the distribution of pressure difference between upper and lower surfaces and the distribution of the thrust force. In efficiency calculations, the undulating fins showed promising results. Finally, for the fin, the open characteristics from computed data showed satisfactory conformity with the experimental results.

  2. A Helical Undulator Wave-guide Inverse Free-Electron Laser

    International Nuclear Information System (INIS)

    With recent success in high gradient, high-energy gain IFEL experiments at the UCLA Neptune Laboratory, future experiments are now being contemplated. The Neptune IFEL was designed to use a tightly focused, highly diffracting, near-TW peak power 10 micron laser. This choice of laser focusing, driven by power-handling limitations of the optics near the interaction region, led to design and use of a very complex undulator, and to sensitivity to both laser misalignment and focusing errors. As these effects limited the performance of the IFEL experiment, a next generation experiment at Neptune has been studied which avoids the use of a highly diffractive laser beam through use of a waveguide. We discuss here the choice of low-loss waveguide, guided mode characteristics and likely power limitations. We also examine a preferred undulator design, which is chosen to be helical in order to maximize the acceleration achieved for a given power. With the limitations of these laser and undulator choices in mind, we show the expected performance of the IFEL using 1D simulations. Three-dimensional effects are examined, in the context of use of a solenoid for focusing and acceleration enhancement

  3. Baseline for coal powered plants

    International Nuclear Information System (INIS)

    Frequently, the cost performance of a specific power plant is measured by comparing the cost with the statistical average cost of plants through the industry. Unless all of the variables have been considered, this comparison may draw a misleading conclusion. The capital cost of a power plant varies with time (year of commercial operation and construction duration) due to the effect of inflation. Examine these cost data in detail revels that the variation in the cost is very wide. For example, published data shows that the ratio between the highest to the lowest cost per KW is more than 4 to 1 for the plants that commenced operation in 1984. The wide variation of the capital costs is explained below in relation to various influencing factors, differing conditions, and scope of work. This paper provides a defined baseline coal-fired plant, an analysis of its capital costs, and a discussion of the reasons for such wide variation

  4. TWRS privatization process technical baseline

    Energy Technology Data Exchange (ETDEWEB)

    Orme, R.M.

    1996-09-13

    The U.S. Department of Energy (DOE) is planning a two-phased program for the remediation of Hanford tank waste. Phase 1 is a pilot program to demonstrate the procurement of treatment services. The volume of waste treated during the Phase 1 is a small percentage of the tank waste. During Phase 2, DOE intends to procure treatment services for the balance of the waste. The TWRS Privatization Process Technical Baseline (PPTB) provides a summary level flowsheet/mass balance of tank waste treatment operations which is consistent with the tank inventory information, waste feed staging studies, and privatization guidelines currently available. The PPTB will be revised periodically as privatized processing concepts are crystallized.

  5. Integrated Baseline Review (IBR) Handbook

    Science.gov (United States)

    Fleming, Jon F.; Kehrer, Kristen C.

    2016-01-01

    The purpose of this handbook is intended to be a how-to guide to prepare for, conduct, and close-out an Integrated Baseline Review (IBR). It discusses the steps that should be considered, describes roles and responsibilities, tips for tailoring the IBR based on risk, cost, and need for management insight, and provides lessons learned from past IBRs. Appendices contain example documentation typically used in connection with an IBR. Note that these appendices are examples only, and should be tailored to meet the needs of individual projects and contracts. Following the guidance in this handbook will help customers and suppliers preparing for an IBR understand the expectations of the IBR, and ensure that the IBR meets the requirements for both in-house and contract efforts.

  6. Pinellas Plant Environmental Baseline Report

    Energy Technology Data Exchange (ETDEWEB)

    1997-06-01

    The Pinellas Plant has been part of the Department of Energy`s (DOE) nuclear weapons complex since the plant opened in 1957. In March 1995, the DOE sold the Pinellas Plant to the Pinellas County Industry Council (PCIC). DOE has leased back a large portion of the plant site to facilitate transition to alternate use and safe shutdown. The current mission is to achieve a safe transition of the facility from defense production and prepare the site for alternative uses as a community resource for economic development. Toward that effort, the Pinellas Plant Environmental Baseline Report (EBR) discusses the current and past environmental conditions of the plant site. Information for the EBR is obtained from plant records. Historical process and chemical usage information for each area is reviewed during area characterizations.

  7. 327 Building hazard baseline document

    International Nuclear Information System (INIS)

    This document identifies the hazards in the 327 Building at the time that a facility walk through was performed during FY99, presents a PHA of stabilization and deactivation activities, and provides a basis for the hazard evaluation and accident analysis that will be developed in the 327 Building Basis for Interim Operation (BIO). Activities addressed in this hazard baseline document include: (1) Stabilization and deactivation activities in preparation for eventual decommissioning of the 327 Building and the routine handling, processing, and shipment of waste to support these activities. (2) 324/327 Building Minimum Safe Project engineering and maintenance activities to maintain the building and systems viable--especially the Safety SSCs--to allow stabilization, deactivation, and waste handling activities with a minimum of risk to workers, the public, and the environment

  8. Atlantic NAD 83 SLA Baseline Tangents

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains baseline tangent lines in ArcGIS shapefile format for the BOEM Atlantic Region. Baseline tangent lines are typically bay or river closing...

  9. Atlantic NAD 83 SLA Baseline Points

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains baseline points in ArcGIS shapefile format for the BOEM Atlantic Region. Baseline points are the discrete coordinate points along the...

  10. Prototyping of the ILC Baseline Positron Target

    Energy Technology Data Exchange (ETDEWEB)

    Gronberg, J; Brooksby, C; Piggott, T; Abbott, R; Javedani, J; Cook, E

    2012-02-29

    The ILC positron system uses novel helical undulators to create a powerful photon beam from the main electron beam. This beam is passed through a titanium target to convert it into electron-positron pairs. The target is constructed as a 1 m diameter wheel spinning at 2000 RPM to smear the 1 ms ILC pulse train over 10 cm. A pulsed flux concentrating magnet is used to increase the positron capture efficiency. It is cooled to liquid nitrogen temperatures to maximize the flatness of the magnetic field over the 1 ms ILC pulse train. We report on prototyping effort on this system.

  11. Baseline Graphite Characterization: First Billet

    Energy Technology Data Exchange (ETDEWEB)

    Mark C. Carroll; Joe Lords; David Rohrbaugh

    2010-09-01

    The Next Generation Nuclear Plant Project Graphite Research and Development program is currently establishing the safe operating envelope of graphite core components for a very high temperature reactor design. To meet this goal, the program is generating the extensive amount of quantitative data necessary for predicting the behavior and operating performance of the available nuclear graphite grades. In order determine the in-service behavior of the graphite for the latest proposed designs, two main programs are underway. The first, the Advanced Graphite Creep (AGC) program, is a set of experiments that are designed to evaluate the irradiated properties and behavior of nuclear grade graphite over a large spectrum of temperatures, neutron fluences, and compressive loads. Despite the aggressive experimental matrix that comprises the set of AGC test runs, a limited amount of data can be generated based upon the availability of space within the Advanced Test Reactor and the geometric constraints placed on the AGC specimens that will be inserted. In order to supplement the AGC data set, the Baseline Graphite Characterization program will endeavor to provide supplemental data that will characterize the inherent property variability in nuclear-grade graphite without the testing constraints of the AGC program. This variability in properties is a natural artifact of graphite due to the geologic raw materials that are utilized in its production. This variability will be quantified not only within a single billet of as-produced graphite, but also from billets within a single lot, billets from different lots of the same grade, and across different billets of the numerous grades of nuclear graphite that are presently available. The thorough understanding of this variability will provide added detail to the irradiated property data, and provide a more thorough understanding of the behavior of graphite that will be used in reactor design and licensing. This report covers the

  12. European XFEL (in Polish)

    OpenAIRE

    Romaniuk, R S

    2013-01-01

    European X-Ray FEL – free electron laser is under construction in DESY Hamburg. It is scheduled to be operational at 2015/16 at a cost more than 1 billion Euro. The laser uses SASE method to generate x-ray light. It is propelled by an electron linac of 17,5GeV energy and more than 2km in length. The linac uses superconducting SRF TESLA technology working at 1,3 GHz in frequency. The prototype of EXFEL is FLASH Laser (200 m in length), where the “proof of principle” was checked, and from the t...

  13. European XFEL (in Polish)

    CERN Document Server

    Romaniuk, R S

    2013-01-01

    European X-Ray FEL – free electron laser is under construction in DESY Hamburg. It is scheduled to be operational at 2015/16 at a cost more than 1 billion Euro. The laser uses SASE method to generate x-ray light. It is propelled by an electron linac of 17,5GeV energy and more than 2km in length. The linac uses superconducting SRF TESLA technology working at 1,3 GHz in frequency. The prototype of EXFEL is FLASH Laser (200 m in length), where the “proof of principle” was checked, and from the technologies were transferred to the bigger machine. The project was stared in the nineties by building a TTF Laboratory -Tesla Test Facility. The EXFEL laser is a child of a much bigger teraelectronovolt collider project TESLA (now abandoned in Germany but undertaken by international community in a form the ILC). A number of experts and young researchers from Poland participate in the design, construction and research of the FLASH and EXFEL lasers.

  14. 2016 Annual Technology Baseline (ATB)

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Wesley; Kurup, Parthiv; Hand, Maureen; Feldman, David; Sigrin, Benjamin; Lantz, Eric; Stehly, Tyler; Augustine, Chad; Turchi, Craig; O' Connor, Patrick; Waldoch, Connor

    2016-09-01

    Consistent cost and performance data for various electricity generation technologies can be difficult to find and may change frequently for certain technologies. With the Annual Technology Baseline (ATB), National Renewable Energy Laboratory provides an organized and centralized dataset that was reviewed by internal and external experts. It uses the best information from the Department of Energy laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information. The ATB includes both a presentation with notes (PDF) and an associated Excel Workbook. The ATB includes the following electricity generation technologies: land-based wind; offshore wind; utility-scale solar PV; concentrating solar power; geothermal power; hydropower plants (upgrades to existing facilities, powering non-powered dams, and new stream-reach development); conventional coal; coal with carbon capture and sequestration; integrated gasification combined cycle coal; natural gas combustion turbines; natural gas combined cycle; conventional biopower. Nuclear laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information.

  15. Space Station-Baseline Configuration

    Science.gov (United States)

    1989-01-01

    In response to President Reagan's directive to NASA to develop a permanent marned Space Station within a decade, part of the State of the Union message to Congress on January 25, 1984, NASA and the Administration adopted a phased approach to Station development. This approach provided an initial capability at reduced costs, to be followed by an enhanced Space Station capability in the future. This illustration depicts the baseline configuration, which features a 110-meter-long horizontal boom with four pressurized modules attached in the middle. Located at each end are four photovoltaic arrays generating a total of 75-kW of power. Two attachment points for external payloads are provided along this boom. The four pressurized modules include the following: A laboratory and habitation module provided by the United States; two additional laboratories, one each provided by the European Space Agency (ESA) and Japan; and an ESA-provided Man-Tended Free Flyer, a pressurized module capable of operations both attached to and separate from the Space Station core. Canada was expected to provide the first increment of a Mobile Serving System.

  16. Hydrogeology baseline study Aurora Mine

    International Nuclear Information System (INIS)

    A baseline hydrogeologic study was conducted in the area of Syncrude's proposed Aurora Mine in order to develop a conceptual regional hydrogeologic model for the area that could be used to understand groundwater flow conditions. Geologic information was obtained from over 2,000 coreholes and from data obtained between 1980 and 1996 regarding water level for the basal aquifer. A 3-D numerical groundwater flow model was developed to provide quantitative estimates of the potential environmental impacts of the proposed mining operations on the groundwater flow system. The information was presented in the context of a regional study area which encompassed much of the Athabasca Oil Sands Region, and a local study area which was defined by the lowlands of the Muskeg River Basin. Characteristics of the topography, hydrology, climate, geology, and hydrogeology of the region are described. The conclusion is that groundwater flow in the aquifer occurs mostly in a westerly direction beneath the Aurora Mine towards its inferred discharge location along the Athabasca River. Baseflow in the Muskeg River is mostly related to discharge from shallow surficial aquifers. Water in the river under baseflow conditions was fresh, of calcium-carbonate type, with very little indication of mineralization associated with deeper groundwater in the Aurora Mine area. 44 refs., 5 tabs., 31 figs

  17. 324 Building Baseline Radiological Characterization

    International Nuclear Information System (INIS)

    This report documents the analysis of radiological data collected as part of the characterization study performed in 1998. The study was performed to create a baseline of the radiological conditions in the 324 Building. A total of 85 technical (100 square centimeter (cm2)) smears were collected from the Room 147 hoods, the Shielded Materials Facility (SMF), and the Radiochemical Engineering Cells (REC). Exposure rate readings (window open and window closed) were taken at a distance of 2.5 centimeters (cm) and 30 cm from the surface of each smear. Gross beta-gamma and alpha counts of each smear were also performed. The smear samples were analyzed by gamma energy analysis (GEA). Alpha energy analysis (AEA) and strontium-90 analysis were also performed on selected smears. GEA results for one or more samples reported the presence of manganese-54, cobalt-60, silver-108m antimony-125, cesium-134, cesium-137, europium-154, europium-155, and americium-241. AEA results reported the presence of plutonium-239/240, plutonium-238/241Am, curium-243/244, curium-242, and americium-243. Tables 5 through 9 present a summary by location of the estimated maximum removable and total contamination levels in the Room 147 hoods, the SMF, and the REC. The smear sample survey data and laboratory analytical results are presented in tabular form by sample in Appendix A. The Appendix A tables combine survey data documented in radiological survey reports found in Appendix B and laboratory analytical results reported in the 324 Building Physical and Radiological Characterization Study (Berk, Hill, and Landsman 1998), supplemented by the laboratory analytical results found in Appendix C.

  18. An experimental study of the beam-steering effect on the FEL gain at LEUTL's segmented undulators

    International Nuclear Information System (INIS)

    The electron trajectories at the low-energy undulator test line (LEUTL), a self-amplified spontaneous emission (SASE) free-electron laser (FEL) facility at Argonne, were routinely corrected during the user run in order to deliver maximum radiation power to the user. Even though we knew from experience that SASE gain at the segmented undulators was dependent on the trajectory, the quantitative understanding of steering effects associated with the specific trajectory was lacking. Recently Tanaka et al. (1) proposed an analytical model for the single-kick error (SKE) effect. Since the LEUTL has eight segmented undulators, we performed the first measurement of SKE on the FEL gain. In the experiments we varied the corrector strength up to the critical angle, and the gain over the undulator was measured for each corrector setting. The results were compared with the analytical model and GENESIS simulations. We also measured the e-beam positions and SASE intensities over the undulators. The experimental data were analyzed and their results were reproduced by GENESIS simulation. The simulation condition, including the measured not-so-ideal trajectory, was used to predict performance enhancements that could be achieved by upgrading ebeam current, e-beam emittance, or trajectory control.

  19. The U5.0 Undulator for the Advanced Light Source

    International Nuclear Information System (INIS)

    The U5.0 Undulator, an 89 period, 5 cm period length, 4.6 m long insertion device has been designed, is being fabricated, and is scheduled for completion in early 1992. This undulator will be the first high brightness source, in the 50 to 1,500 eV range, for the Advanced Light Source at the Lawrence Berkeley Laboratory. A hybrid magnetic configuration using Nd--Fe--B permanent magnet material and vanadium permendur poles has been selected to achieve the field quality needed to meet performance requirements. The magnetic structure is modular with each half consisting of five assembly sections, which provide the periodic structure, and end structures, for entrance and exit correction, mounted on a steel backing beam. Each assembly section consists of 35 half-period pole assemblies bolted to a mount. The required 0.837 T effective peak field at a 1.4 cm gap has been verified with model measurements. Vertical field integral correction is accomplished with the end structures, each having an arrangement of permanent magnet rotors which will be adjusted to minimize electron beam missteering over the undulator operating field range. To reduce the effect of environmental fields, the steel backing beams are connected through parallel, low-reluctance, Ni--Fe hinges. The magnetic structure is connected through four rollernuts to the drive system that provides gap adjustment with an arrangement of roller screws, chain drives, a gear reduction unit, and a stepper motor driven by a closed loop control system. Magnetic structure and drive system support are from a 2.4 m high structure which includes a support base with four vertical supports. The vacuum chamber design is a two-piece machined and welded 5083-H321 aluminum construction of 5.1 m length. Pumping is with a combination of ion, titanium sublimation pump and nonevaporable getter pumps. Magnetic design, subsystem design, and fabrication progress are presented

  20. Canted Undulator Upgrade for GeoSoilEnviroCARS Sector 13 at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, Stephen

    2013-02-02

    Support for the beamline component of the canted undulator upgrade of Sector 13 (GeoSoilEnviroCARS; managed and operated by the University of Chicago) at the Advanced Photon Source (APS; Argonne National Laboratory) was received from three agencies (equally divided): NASA-SRLIDAP (now LARS), NSF-EAR-IF (ARRA) and DOE-Single Investigator Small Group (SISGR). The associated accelerator components (undulators, canted front end) were provided by the APS using DOE-ARRA funding. The intellectual merit of the research enabled by the upgrade lies in advancing our knowledge of the composition, structure and properties of earth materials; the processes they control; and the processes that produce them. The upgrade will facilitate scientific advances in the following areas: high pressure mineral physics and chemistry, non-crystalline and nano-crystalline materials at high pressure, chemistry of hydrothermal fluids, reactions at mineral-water interfaces, biogeochemistry, oxidation states of magmas, flow dynamics of fluids and solids, and cosmochemistry. The upgrade, allowing the microprobe to operate 100% of the time and the high pressure and surface scattering and spectroscopy instruments to receive beam time increases, will facilitate much more efficient use of the substantial investment in these instruments. The broad scientific community will benefit by the increase in the number of scientists who conduct cutting-edge research at GSECARS. The user program in stations 13ID-C (interface scattering) and 13ID-D (laser heated diamond anvil cell and large volume press) recommenced in June 2012. The operation of the 13ID-E microprobe station began in the Fall 2012 cycle (Oct.-Dec 2012). The upgraded canted beamlines double the amount of undulator beam time at Sector 13 and provide new capabilities including extended operations of the X-ray microprobe down to the sulfur K edge and enhanced brightness at high energy. The availability of the upgraded beamlines will advance the

  1. Hazard Baseline Downgrade Effluent Treatment Facility

    International Nuclear Information System (INIS)

    This Hazard Baseline Downgrade reviews the Effluent Treatment Facility, in accordance with Department of Energy Order 5480.23, WSRC11Q Facility Safety Document Manual, DOE-STD-1027-92, and DOE-EM-STD-5502-94. It provides a baseline grouping based on the chemical and radiological hazards associated with the facility. The Determination of the baseline grouping for ETF will aid in establishing the appropriate set of standards for the facility

  2. Hospital doctors' assessment of baseline spirometry.

    OpenAIRE

    Stephenson, N.; Morgan, R.; Abdel-Rahman-Abdel-Wahab, E.; Turnbull, C. J.

    1998-01-01

    Baseline spirometry is useful in diagnosing and managing pulmonary disease. In a questionnaire survey of 100 hospital doctors in two hospitals in the Mersey region, their views and ability to interpret baseline spirometry was assessed. Of the 70 doctors who responded, 65% felt they could accurately interpret baseline spirometry. However, only 12% accurately interpreted all five vitalographs in the questionnaire. The majority (72%) felt they had not had adequate teaching in interpretation of s...

  3. Simulation and measurement of the electrostatic beam kicker in the low-energy undulator test line

    International Nuclear Information System (INIS)

    An electrostatic kicker has been constructed for use in the Low-Energy Undulator Test Line (LEUTL) at the Advanced Photon Source (APS). The function of the kicker is to limit the amount of beam current to be accelerated by the APS linac. Two electrodes within the kicker create an electric field that adjusts the trajectory of the beam. This paper will explore the static fields that are set up between the offset electrode plates and determine the reaction of the beam to this field. The kicker was numerically simulated using the electromagnetic solver package MAFIA [1

  4. Emittance measurements of CESR using the emitted radiation from a short-period undulator

    International Nuclear Information System (INIS)

    The horizontal and vertical emittance of the Cornell Electron Storage Ring (CESR) was measured using the radiation emitted from a short-period (3.3 cm) 123-pole undulator. Average horizontal and vertical emittances measured by this technique were 80 nm-rad and 1.75 nm-rad, respectively. These compare favorably with the results from a charge-coupled device (CCD) system routinely used at CESR and with the calculated values of 65 nm-rad and ∼1 nm-rad for the horizontal and vertical emittances respectively

  5. Controlling the morphology of carbon nanotube arrays: from spinnable forests to undulating foams

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingying [Los Alamos National Laboratory; Zou, Guifu [Los Alamos National Laboratory; Stan, Liliana [Los Alamos National Laboratory; Hawley, Marilyn E [Los Alamos National Laboratory; Sheehan, Chris J [Los Alamos National Laboratory; Zhu, Yuntain [Los Alamos National Laboratory; Jia, Quanxi [Los Alamos National Laboratory; Doorn, Stephen K [NCSU; Htoon, Han [NCSU

    2009-01-01

    By controlling catalyst pretreatment conditions, we demonstrate that the degree of spinnability of carbon nanotubes (CNTs) is closely related to the morphology of CNT arrays. Shortest catalyst pretreatment time led to CNT arrays with the best spinnability, while prolonged pretreatment resulted in coarsening of catalyst particles and non-spinnable CNTs. We further demonstrate the growth of undulating CNT arrays with uniform and tunable waviness by controlling the coalescence of catalyst particles. The CNT arrays can be tuned from well-aligned, spinnable forests to uniformly wavy, foam-like films by controlling catalyst pretreatment conditions.

  6. An acoustical research of the undulating wooden ceiling in the Vyborg Library

    DEFF Research Database (Denmark)

    Mortensen, Bo

    2004-01-01

    Much has been written about the Undulating Ceiling at the lecture hall of the Vyborg Library. Alvar Aalto himself claimed the ceiling to be "ninety-nine per cent acoustically perfect" and the sketches showing the acoustical considerations behind the ceiling-design is often reproduced. But how did...... it actually function? Did the wave form have the claimed acoustical avantages or could the ceiling as well have been horisontal. Comprehensive acoustical investigations have been carried out including acoustical measurements in a 1:20 scale model and calculations in a 3D computer model of the lecture...

  7. Magnetic field measurements of a superconducting undulator for a Harmonic Generation FEL experiment at the NSLS

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, L.; Ingold, G.; Ben-Zvi, I.; Krinsky, S.; Yu, L.H.; Sampson, W.; Robins, K.

    1993-07-01

    An 18mm period, 0.54 Tesla, 8mm gap superconducting undulator with both horizontal and vertical focusing has been built and tested. This magnet, which is fabricated in 25 cm length sections, is being tested for use in the radiator section (total magnet length of 1.5 m) of the Harmonic Generation Free Electron Laser experiment at the National Synchrotron Light Source - Accelerator Test Facility at Brookhaven National Lab., in collaboration with Grumman Corp. The measurement system is outlined, sources and estimates of errors are described, and some magnetic field data are presented and discussed.

  8. Numerical modeling of shoreline undulations part 2: Varying wave climate and comparison with observations

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg; Fredsøe, Jørgen

    2013-01-01

    waves with a directional spreading. In this paper, these findings are extended to firstly include the effect of a varying wave climate on the shoreline morphology and secondly, to tune the model to two naturally occurring shorelines. It is found that the effect of a variable wave climate is to slow down...... the development of the morphology and in some cases to inhibit the formation of shore-parallel spits at the crest of the undulations. On one of the natural shorelines, the west coast of Namibia, the shore is exposed to very obliquely waves from one main direction. Here, the shoreline model is able to...

  9. Development of an electromagnetic phase shifter using a pair of cut-core coils for a cross undulator

    International Nuclear Information System (INIS)

    This paper describes the development of a phase shifter that can be used in cross undulators for fast polarization switching. The phase shifter is composed of a pair of cut-core coils and a thin-walled stainless steel duct. Evaluation of the magnetic fields of the phase shifter indicates that the switching frequency of this simple and low-cost device can exceed 30 Hz. - Highlights: • We have developed a simple phase shifter that can be used in a cross undulator for fast polarization switching. • The phase shifter is low-cost and it uses a pair of cut-core coil. • The polarization switching of the undulator light can exceed 30 Hz. • The phase shifter has the potential to make shot-by-shot polarization control for X-ray free electron laser

  10. Thermomechanical analysis of the white-beam slits for a wiggler/undulator beamline at the Advanced Photon Source

    International Nuclear Information System (INIS)

    A set of precision, vertical, white-beam slits has been designed for an undulator/wiggler beamline at the Advanced Photon Source (APS). The slit, a knife-edge-type precision device, is required to have very small thermal distortion during operation with beam. The traditional slit consists of a cooling block and an OFHC cooling channel inside the block. The design consists of one large block and an OFHC cooling tube (filled with copper mesh) brazed inside the large block. This design will accommodate the x-ray source from both undulators and wigglers. Due to the powerful x-ray heat flux coming from APS Undulator A, it is an exceedingly difficult problem to reduce the thermal distortion to less than 50 μm as required by some users

  11. Combined electromagnetic and permanent magnet undulator to achieve higher field and easier field variation without mechanical movement

    Energy Technology Data Exchange (ETDEWEB)

    Bogachenkov, V.A.; Papadichev, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)

    1995-12-31

    Hybrid or pure permanent magnet undulators (PMU) are widely used because they have high field quality, allow easy field correction and do not consume power. Their main drawback is the necessity of moving one half of the magnet relative to the other to change field value, which requires a high precision, remotely controlled (and thus costly) driving system On the other hand, electromagnetic undulatory (EMU) have no problem with field variation, but consume too much power (100 - 400 kW) for high fields. Adding permanent magnets to EMU results in a considerable decrease of power consumption, while retaining the advantage of easily changing field level. A model of a CW combined EM+PM plane undulator having a 4.8 cm period and 8 periods long is described. It is simple in design and cheap in manufacturing: magnet yokes are made of soft steel rings in which 1.6 cm air gaps were cut to form pole faces. Odd yokes are placed to one side of the undulator axis and even yokes to the other with the air gaps on the axis. Each set of yokes is excited by its own separate winding of simple racetrack shape. Undulator deflection parameter K = 1.1 (B = 2.4 kG) can be reached at a 0.78kW power level, i.e., less than 100 W per period, while without PM only a maximum K = 0.8 can be obtained and requires 4 kW power. No water cooling is needed, which greatly simplifies undulator design. The undulator was not optimized relative to the axial-air-gap to ring-width ratio: one might expect some increase in field level for thinner rings. Field amplitude depends also on relative transverse position of odd and even pole faces.

  12. Undulant Universe

    Energy Technology Data Exchange (ETDEWEB)

    Barenboim, Gabriela; /Valencia U.; Mena, Olga; Quigg, Chris; /Fermilab

    2004-12-01

    If the equation of state for ''dark energy'' varies periodically, the expansion of the Universe may have undergone alternating eras of acceleration and deceleration. We examine a specific form that survives existing observational tests, does not single out the present state of the Universe as exceptional, and suggests a future much like the matter-dominated past: a smooth expansion without a final inflationary epoch.

  13. Longer-Baseline Telescopes Using Quantum Repeaters

    OpenAIRE

    Gottesman, Daniel; Jennewein, Thomas; Croke, Sarah

    2011-01-01

    We present an approach to building interferometric telescopes using ideas of quantum information. Current optical interferometers have limited baseline lengths, and thus limited resolution, because of noise and loss of signal due to the transmission of photons between the telescopes. The technology of quantum repeaters has the potential to eliminate this limit, allowing in principle interferometers with arbitrarily long baselines.

  14. NOVEL CHAMBER DESIGN FOR AN IN-VACUUM CRYO-COOLED MINI-GAP UNDULATOR

    International Nuclear Information System (INIS)

    A stainless steel, Ultra-High Vacuum (UHV) chamber, featuring a large vertical rectangular port (53''W by 16''H), has been fabricated to house the one-meter magnet assembly of a newly installed undulator insertion device for beamline X-25 at the National Synchrotron Light Source. To achieve UHV, the new chamber is equipped with a differential ion pump, NEG pump, nude ion gauge, residual gas analyzer, and an all metal roughing valve. Temperature of the magnet assembly is maintained below 90 C during vacuum bake. The large rectangular port cover is sealed to the main flange of the chamber using a one-piece flat aluminum gasket and special sealing surfaces developed exclusively by Nor-Cal Products, Inc. The large flange provides easy access to the gap of the installed magnet girders for in situ magnetic measurements and shimming. Special window ports were designed into the cover and chamber for manipulation of optical micrometers external to the chamber to provide precise measurements of the in-vacuum magnet gap. The vacuum chamber assembly features independently vacuum-isolated feedthroughs that can be used for either water-or-cryogenic refrigeration-cooling of the monolithic magnet girders. This would allow for cryogenic-cooled permanent magnet operation and has been successfully tested within temperature range of +100 C to -150 C. Details of the undulator assembly for beamline X-25 is described in the paper

  15. Design, Implementation and Control of a Fish Robot with Undulating Fins

    Directory of Open Access Journals (Sweden)

    Mohsen Siahmansouri

    2011-11-01

    Full Text Available Biomimetic robots can potentially perform better than conventional robots in underwater vehicle designing. This paper describes the design of the propulsion system and depth control of a robotic fish. In this study, inspired by knife fish, we have designed and implemented an undulating fin to produce propulsive force. This undulating fin is a segmental anal fin that produces sinusoidal wave to propel the robot. The relationship between the individual fin segment and phase angles with the overall fin trajectory has also been discussed. This propulsive force can be adjusted and directed for fish robot manoeuvre by a mechanical system with two servomotors. These servomotors regulate the direction and depth of swimming. A wireless remote control system is designed to adjust the servomotors which enables us to control revolution, speed and phase differences of neighbor servomotors of fins. Finally, Field trials are conducted in an outdoor pool to demonstrate the relationship between robotic fish speed and fin parameters like phase difference, the number of phase and undulatory amplitude.

  16. The NSLS X13 Mini-Gap Undulator: Design and Performance

    International Nuclear Information System (INIS)

    An in-vacuum short-period mini-gap undulator (MGU) has recently been installed within the National Synchrotron Light Source (NSLS) X13 straight-section. The MGU is a hybrid design, consisting of NdFeB permanent magnets and vanadium permendur poles. The MGU period is 1.25 cm, the overall length is 35 cm, and the gap can be varied between 3.3 and 11 mm. The higher magnetic field provided by the hybrid design supersedes that of the previous X13 undulator device (IVUN), allowing for a greater tunability. Operating down to a magnetic gap of 3.3 mm, the on-axis magnetic field is 0.92 Tesla, corresponding to a deflection parameter K∼1.07. The performance of the MGU has been measured using a single crystal spectrometer. At a gap of 3.3 mm, the MGU's fundamental energy was recorded at 3.7 keV with a brightness of 4x1017 ph/sec/mm2/mrad2/0.1%BW/300mA

  17. Effect of undulators on the stored electron beam of Indus-2

    Institute of Scientific and Technical Information of China (English)

    Abdurrahim; A.D.Ghodke

    2015-01-01

    Indus-2 is an Indian synchrotron light source,operating at 2.5 GeV and generating synchrotron radiation from its bending magnets.In order to provide more intense synchrotron radiation to the synchrotron users,there is a plan to install five insertion devices in the Indus-2 storage ring.In the first phase of installation of insertion devices,there is a proposal to install two out-vacuum pure permanent magnet linearly polarized undulators in long straight sections of the Indus-2 storage ring.The presence of the insertion devices in the ring has inevitable effects on beam parameters like betatron tune,betatron amplitude function,closed orbit,emittance,energy spread and dynamic aperture etc.In this paper,the effect of two undulators on the above mentioned parameters of the Indus-2 stored electron beam at 2.5 GeV is presented.Moreover a correction scheme for the restoration of the betatron tune and amplitude function is also presented.

  18. Analysis of baroreflex sensitivity during undulation pump ventricular assist device support.

    Science.gov (United States)

    Liu, Hongjian; Shiraishi, Yasuyuki; Zhang, Xiumin; Song, Hojin; Saijo, Yoshifumi; Baba, Atsushi; Yambe, Tomoyuki; Abe, Yusuke; Imachi, Kou

    2009-07-01

    The aim of this study was to examine the baroreflex sensitivity (BRS), which involves the autonomic nervous system, in a goat with a chronically implanted undulation pump ventricular assist device (UPVAD). The UPVAD involved transforming the rotation of a brushless DC motor into an undulating motion by a disc attached via a special linking mechanism, and a jellyfish valve in the outflow cannula to prevent diastolic backflow. The pump was implanted into the thoracic cavity of a goat by a left thoracotomy, and the inflow and outflow cannulae were sutured to the apex of the left ventricle and to the descending aorta, respectively. The driving cable was wired percutaneously to an external controller. Electrocardiogram and hemodynamic waveforms were recorded at a sampling frequency of 1 kHz. BRS was determined when awake by the slope of the linear regression of R-R interval against mean arterial pressure changes, which were induced by the administration of methoxamine hydrochloride, both with continuous driving of the UPVAD as well as without assistance. BRS values during the UPVAD support and without assistance were 1.60 +/- 0.30 msec/mm Hg and 0.98 +/- 0.22 msec/mm Hg (n = 5, P < 0.05), respectively. BRS was significantly improved during left ventricular assistance. Therefore, UPVAD support might decrease sympathetic nerve activity and increase parasympathetic nerve activity to improve both microcirculation and organ function. PMID:19566735

  19. A tapered undulator experiment at the ELBE far infrared hybrid-resonator oscillator free electron laser

    International Nuclear Information System (INIS)

    A tapered undulator experiment was carried out at the ELBE far-infrared free electron laser (FEL). The oscillator FEL makes use of a hybrid optical resonator. The main motivation was to see whether the presence of a dispersive medium in the form of a waveguide in the resonator has any effect on the outcome. The FEL saturated power and the wavelength shifts have been measured as a function of both positive as well as negative undulator field amplitude tapering. In contrast to the typical high-gain FELs where positive tapering proves beneficial for the output power we observed an improvement of performance at negative taper. During the same experiments we studied the characteristics of the detuning curves. The width of the curves indicates a maximum small signal gain for zero taper while the output peak power increases with negative taper. The saturated power output, the detuning curve characteristics, and the wavelength shifts agrees with the theoretical predictions. Details of the experiment are presented.

  20. Magnetic measurements of the NSLS [National Synchrotron Light Source] soft x-ray undulator

    International Nuclear Information System (INIS)

    The Soft X-Ray Undulator Magnet was installed in the X-ray Ring (X1 beam line) at the National Synchrotron Light Source at Brookhaven National Laboratory in June 1988. Prior to its installation extensive magnetic measurements were performed at the NSLS Magnetic Measurements Lab in order to determine the operating values for the end corrector currents, the field quality, and the integrated multipoles associated with the magnet as a function of gap. This report is intended to summarize the results of these measurements. The iron poles are 18mm x 32mm x 86mm, and the Samarium Cobalt permanent magnet blocks are 22mm x 21mm x 110mm. In each of the magnet halves there are 76 slots, 70 of which were filled with two magnets per slot, and 6 of which were left empty (3 each on the upstream and downstream ends of the magnet). These slots were left empty in order to approximate an infinitely long magnet in the algorithm for the magnet block sorting. The magnet period is 80mm, and the gap range is 31--100mm, with field values of 3500 and 200 Gauss respectively. For this gap range the undulator parameter K, where K = 0.934 B(Tesla) λ(cm), ranges from 2.6 to 0.15. 14 figs., 5 tabs

  1. The nuclear-resonance-scattering station at the PETRA II undulator beamline

    Energy Technology Data Exchange (ETDEWEB)

    Franz, H.; Hukelmann, B.; Schneider, J.R. [HASYLAB at DESY (Germany)

    2000-07-15

    PETRA II, a 12 GeV accelerator at DESY, Hamburg, is used to produce synchrotron radiation (SR) for experiments in the hard X-ray regime when it is not running as injector for HERA. The beam from an undulator is split by a diamond crystal in Laue geometry to feed two experimental stations, one of which is now dedicated for nuclear resonance experiments. The X-ray energy may be chosen in the range from 5 to 55 keV covering all isotopes already observed with SR and many interesting candidates for new resonances. Tuning may be performed by optimising the magnetic gap and the storage ring energy. In particular, the opportunities for timing experiments are unique due to a very flexible filling mode of the storage ring. The flux at the sample position is comparable to undulator beams at ESRF. The second beamline covers higher energies up to some 300 keV and may also be used for nuclear resonance experiments.

  2. The nuclear-resonance-scattering station at the PETRA II undulator beamline

    Science.gov (United States)

    Franz, H.; Hukelmann, B.; Schneider, J. R.

    2000-07-01

    PETRA II, a 12 GeV accelerator at DESY, Hamburg, is used to produce synchrotron radiation (SR) for experiments in the hard X-ray regime when it is not running as injector for HERA. The beam from an undulator is split by a diamond crystal in Laue geometry to feed two experimental stations, one of which is now dedicated for nuclear resonance experiments. The X-ray energy may be chosen in the range from 5 to 55 keV covering all isotopes already observed with SR and many interesting candidates for new resonances. Tuning may be performed by optimising the magnetic gap and the storage ring energy. In particular, the opportunities for timing experiments are unique due to a very flexible filling mode of the storage ring. The flux at the sample position is comparable to undulator beams at ESRF. The second beamline covers higher energies up to some 300 keV and may also be used for nuclear resonance experiments.

  3. Quadrupole Magnet Error Sensitivities for FODO-Cell and Triplet Lattices in the LCLS Undulator

    International Nuclear Information System (INIS)

    The error sensitivities of quadrupole magnets in the LCLS FEL undulator are compared for a FODO-cell lattice and for a triplet lattice. The comparisons are made at a radiation wavelength of 1.5 (angstrom), where electron-to-photon phase errors are very sensitive to small trajectory variations in misaligned quadrupoles between the undulator sections. The results show that the triplet lattice is extremely sensitive, with triplet pitch and yaw alignment tolerances of ∼100 (micro)rad. The FODO-cell lattice, with its shorter, weaker quadrupoles is much more error tolerant with pitch and yaw tolerances of ∼2.5 mrad. Several other magnet errors are examined and categorized as trajectory, phase slip, and beam size effects. In nearly all cases, the FODO-cell lattice is much less sensitive with technologically achievable tolerance levels, while the triplet lattice tolerances are, in many cases, near achievable limits and may not be sustainable over the long term. Table 2 presents a brief tolerance comparison for the two lattice types

  4. X1A: Second-generation undulator beamlines serving soft x-ray spectromicroscopy experiments at the NSLS

    International Nuclear Information System (INIS)

    The X1A undulator beamline is being rebuilt with two separate monochromators on its two branches. The new arrangement will deliver spatially coherent beams to imaging experiments, with spectral resolving power of up to 5000, and the capability to optimize the resolving power versus flux. The beamlines will operate simultaneously, and each will use 15 percent of the undulator beam, yet deliver high coherent flux. Because of the small beam divergence, the spherical grating monochromators can operate with fixed exit arms throughout the 250 endash 800 eV range. copyright 1996 American Institute of Physics

  5. Analysis of a static undulation on the surface of a thin dielectric liquid layer formed by dielectrophoresis forces

    OpenAIRE

    Brown, Carl; McHale, Glen; Mottram, Nigel

    2011-01-01

    A layer of insulating liquid of dielectric constant ɛOil and average thickness coats a flat surface at y = 0 at which a one-dimensional sinusoidal potential V(x,0) = VOcos(πx/p) is applied. Dielectrophoresis forces create a static undulation (or “wrinkle”) distortion h(x) of period p at the liquid/air interface. Analytical expressions have been derived for the electrostatic energy and the interfacial energy associated with the surface undulation when h(x) = -(1/2)Acos(2πx/p) yielding a scali...

  6. Design, development, installation and commissioning of water-cooled pre-masks for undulator front-ends of Indus-2

    International Nuclear Information System (INIS)

    Recently two undulators U1 and U2 are installed in Indus-2 storage ring at RRCAT, Indore. When U1 and U2 are put in operation, a bright synchrotron radiation (SR) is produced which is transmitted through the zero degree port of the dipole vacuum chamber. In addition, a part of SR beam from the bending magnets, at the upstream and downstream of the undulator, is also overlapped with the undulator SR beam and transmitted in to the front-end through the same port. The front-end is a long ultra high vacuum (UHV) assembly consisting of water-cooled pre-mask, water-cooled shutters, UHV valves, diagnostic devices, safety shutter, vacuum pumps etc which acts as an interface between Indus-2 ring and beamline. Water-cooled pre- masks have been designed to cut a part of unwanted SR beam from the bending magnets. The pre-mask is a first active component in the undulator front-end which is also capable of absorbing high thermal load due to mis-steering of the SR beam from the undulator in the worst case scenario. The watercooled pre-mask consists of a copper block which has fixed aperture with slant faces to distribute the heat flux over a large surface area. The cooling channels are made on outer periphery of the block. The copper block is vacuum brazed with two conflat flanges of stainless steel at the two ends. The pre-mask is designed to absorb thermal load of 3 kW of synchrotron beam from undulator U1 and 2 kW of synchrotron beam from undulator U2. The thermal analysis of the pre-masks was carried out with the help of ANSYS® and the design was optimized with different cooling configurations. The main design criteria was to limit the maximum temperature of the mask less than 60 °C. This is to avoid substantial thermal outgassing from the heated portion which may deteriorate the ultra high vacuum. Pre-masks have been successfully tested, installed and commissioned with synchrotron beam in the undulator front-ends and are operating under vacuum of 5x10-10 mbar. (author)

  7. Design of high heat load white-beam slits for wiggler/undulator beamlines at the Advanced Photon Source

    International Nuclear Information System (INIS)

    A set of horizontal and vertical white-beam slits has been designed for the Advanced Photon Source wiggler/undulator beamlines at Argonne National Laboratory. While this slit set can handle the high heat flux from on e APS undulator source, it has large enough aperture to be compatible with a wiggler source also. A grazing-incidence, knife-edge configuration has been used in the design to eliminate downstream X-ray scattering. Enhanced heat transfer technology has been used in the water-cooling system. A unique stepping parallelogram driving structure provides precise vertical slit motion with large optical aperture. The full design detail is presented in this paper

  8. Design of high heat load white-beam slits for wiggler/undulator beamlines at the Advanced Photon Source

    International Nuclear Information System (INIS)

    A set of horizontal and vertical white-beam slits has been designed for the Advanced Photon Source wiggler/undulator beamlines at Argonne National Laboratory. While this slit set can handle the high heat flux from one APS undulator source, it has a large enough aperture to be compatible with a wiggler source also. A grazing-incidence, knife-edge configuration has been used in the design to eliminate downstream x-ray scattering. Enhanced heat transfer technology has been used in the water-cooling system. A unique stepping parallelogram driving structure provides precise vertical slit motion with large optical aperture. The full design detail is presented in this paper

  9. A simple method for controlling the line width of SASE X-ray FELs

    International Nuclear Information System (INIS)

    This paper describes a novel single-bunch self-seeding scheme for generating highly monochromatic X-rays from a baseline XFEL undulator. A self-seeded XFEL consists of two undulators with an X-ray monochromator located between them. Previous self-seeding schemes made use of a four-crystal fixed-exit monochromator in Bragg geometry. In such monochromator the X-ray pulse acquires a cm-long path delay, which must be compensated. For a single-bunch self-seeding scheme this requires a long electron beam bypass, implying modifications of the baseline undulator configuration. To avoid this problem, a double bunch self-seeding scheme based on a special photoinjector setup was recently proposed. At variance, here we propose a new time-domain method of monochromatization exploiting a single crystal in the transmission direction, thus avoiding the problem of extra-path delay for the X-ray pulse. The method can be realized using a temporal windowing technique, requiring a magnetic delay for the electron bunch only. When the incident X-ray beam satisfies the Bragg diffraction condition, multiple scattering takes place and the transmittance spectrum in the crystal exhibits an absorption resonance with a narrow linewidth. Then, the temporal waveform of the transmitted radiation pulse is characterized by a long monochromatic wake. The radiation power within this wake is much larger than the shot noise power. At the entrance of the second undulator, the monochromatic wake of the radiation pulse is combined with the delayed electron bunch, and amplified up to saturation level. The proposed setup is extremely simple and composed of as few as two simple elements. These are the crystal and the short magnetic chicane, which accomplishes three tasks by itself. It creates an offset for crystal installation, it removes the electron micro-bunching produced in the first undulator, and it acts as a delay line for temporal windowing. Using a single crystal installed within a short magnetic

  10. The BTFEL, an infrared free-electron laser amplifier based on a new-design short-period superconducting tape undulator

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, M., E-mail: moohyun@postech.edu [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Physics, Postech, Hyoja-dong, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Filippetto, D.; Papadopoulos, C.F. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Pellegrini, C. [Department of Physics, University of California, Los Angeles, CA 90095 (United States); Penn, G.; Prestemon, S. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Sannibale, F., E-mail: fsannibale@lbl.gov [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2011-12-21

    The development of undulator technologies capable of generating sub-cm undulator periods is assuming an increasing importance in X-ray free electron laser (FEL) applications. Indeed, such devices jointly with the high brightness electron beams already demonstrated at operating facilities would allow for lower energy, more compact electron linacs with a beneficial impact on the size and cost of X-ray FEL facilities. A novel design super-conducting undulator is being developed at the Lawrence Berkeley National Laboratory (LBNL) with the potential of sub-cm periods with reasonably large undulator parameter and gap. The potential and capability of such undulator technology need to be experimentally demonstrated. In this paper, the possibility of constructing an infrared FEL by combining the new undulator with the high brightness beam from the APEX injector facility at LBNL is investigated. Calculations show that the resulting FEL, when operated in self-amplified-spontaneous-emission mode, is expected to deliver a saturated power of almost a MW within a {approx}4m undulator length, in a single-spike of coherent radiation at {approx}2{mu}m wavelength. It will be also shown that the small-period of the undulator associated with the relatively low energy of the APEX beam, forces the FEL to operate in a regime with unusual and interesting characteristics. The alternative option of laser seeding the FEL is also briefly examined, showing the potential to reduce the saturation length even further.

  11. The BTFEL, an infrared free-electron laser amplifier based on a new-design short-period superconducting tape undulator

    International Nuclear Information System (INIS)

    The development of undulator technologies capable of generating sub-cm undulator periods is assuming an increasing importance in X-ray free electron laser (FEL) applications. Indeed, such devices jointly with the high brightness electron beams already demonstrated at operating facilities would allow for lower energy, more compact electron linacs with a beneficial impact on the size and cost of X-ray FEL facilities. A novel design super-conducting undulator is being developed at the Lawrence Berkeley National Laboratory (LBNL) with the potential of sub-cm periods with reasonably large undulator parameter and gap. The potential and capability of such undulator technology need to be experimentally demonstrated. In this paper, the possibility of constructing an infrared FEL by combining the new undulator with the high brightness beam from the APEX injector facility at LBNL is investigated. Calculations show that the resulting FEL, when operated in self-amplified-spontaneous-emission mode, is expected to deliver a saturated power of almost a MW within a ∼4m undulator length, in a single-spike of coherent radiation at ∼2μm wavelength. It will be also shown that the small-period of the undulator associated with the relatively low energy of the APEX beam, forces the FEL to operate in a regime with unusual and interesting characteristics. The alternative option of laser seeding the FEL is also briefly examined, showing the potential to reduce the saturation length even further.

  12. TWRS technical baseline database manager definition document

    International Nuclear Information System (INIS)

    This document serves as a guide for using the TWRS Technical Baseline Database Management Systems Engineering (SE) support tool in performing SE activities for the Tank Waste Remediation System (TWRS). This document will provide a consistent interpretation of the relationships between the TWRS Technical Baseline Database Management software and the present TWRS SE practices. The Database Manager currently utilized is the RDD-1000 System manufactured by the Ascent Logic Corporation. In other documents, the term RDD-1000 may be used interchangeably with TWRS Technical Baseline Database Manager

  13. Expected performance of the DEPFET sensor with signal compression: A large format X-ray imager with mega-frame readout capability for the European XFEL

    International Nuclear Information System (INIS)

    The new DSSC (DEPFET sensor with signal compression) detector system is being developed in order to fulfil the requirements of the future XFEL in Hamburg. The instrument will be able to record X-ray images with a maximum frame rate of 5 MHz and to achieve a high dynamic range. The system is based on a silicon pixel sensor with a new designed non-linear-DEPFET as a central amplifier structure. The detector chip is bump-bonded to mixed signal readout ASICs that provide full parallel readout and temporary data storage. The signals coming from the detector are processed by an analog filter, immediately digitized by 8-ENOB ADCs and locally stored in a custom designed memory. The ASICs are designed in 130 nm CMOS technology. During the time gap of 99 ms of the XFEL machine, the digital data are sent off the focal plane to a DAQ electronics that acts as an interface to the back-end of the whole instrument. The pixel sensor has been designed so as to combine high energy resolution at low signal charge with high dynamic range. This has been motivated by the desire to be able to be sensitive to single low energy photons and, at the same time, to measure at other positions of the detector signals corresponding to up to 104 photons of 1 keV. In order to fit this dynamic range into a reasonable output signal swing, achieving at the same time single photon resolution, a strongly non-linear characteristic is required. The new proposed DEPFET provides the required dynamic range compression at the sensor level, considerably facilitating the task of the electronics. At the same time the DEPFET charge handling capacitance is enormously increased with respect to standard DEPFETs. The sensor matrix will comprise 1024x1024 pixels of hexagonal shape with a side-length of 136μm. The simultaneous implementation of the 5 MHz frame rate, of the single low-energy photon resolution and of the high dynamic range goes beyond all the existing instruments and requires the development of new

  14. Radiological considerations in the operation of the low-energy undulator test line (LEUTL).

    Energy Technology Data Exchange (ETDEWEB)

    Moe, H.J.

    1998-11-11

    The Low-Energy Undulator Test Line (LEUTL) is a facility that uses the existing APS linac to accelerate electrons up to an energy of 700 MeV. These electrons are transported through the Pm into a portion of the booster synchrotrons and on into the LEUTL main enclosure (MIL 97). Figure 1 shows the layout of the LEUTL building, which consists of an earth-benned concrete enclosure and an end-station building. The concrete enclosure houses the electron beamline, test undulator, and beam dump. This facility is about 51 m long and 3.66 m wide. Technical components and diagnostics for characterizing the undulator light are found in the end station. This building has about 111 m{sup 2} of floor space. This note deals with the radiological considerations of operations using electrons up to 700 MeV and at power levels up to the safety envelope of 1 kW. Previous radiological considerations for electron and positron operations in the linac, PAR, and synchrotrons have been addressed else-where (MOE 93a, 93b, and 93c). Much of the methodology discussed in the previous writeups, as well as in MOE 94, has been used in the computations in this note. The radiological aspects that are addressed include the following: prompt secondary radiation (bremsstrahlung, giant resonance neutrons, medium- and high-energy neutrons) produced by electrons interacting in a beam stop or in component structures; skyshine radiation, which produces a radiation field in nearby areas and at the nearest off-site location; radioactive gases produced by neutron irradiation of air in the vicinity of a particle loss site; noxious gases (ozone and others) produced in air by the escaping bremsstrahlung radiation that results from absorbing particles in the components; activation of the LEUTL components that results in a residual radiation field in the vicinity of these materials following shutdown; potential activation of water used for cooling the magnets and other purposes in the tunnel; and evaluation of the

  15. Radiological considerations in the operation of the low-energy undulator test line (LEUTL)

    International Nuclear Information System (INIS)

    The Low-Energy Undulator Test Line (LEUTL) is a facility that uses the existing APS linac to accelerate electrons up to an energy of 700 MeV. These electrons are transported through the Pm into a portion of the booster synchrotrons and on into the LEUTL main enclosure (MIL 97). Figure 1 shows the layout of the LEUTL building, which consists of an earth-benned concrete enclosure and an end-station building. The concrete enclosure houses the electron beamline, test undulator, and beam dump. This facility is about 51 m long and 3.66 m wide. Technical components and diagnostics for characterizing the undulator light are found in the end station. This building has about 111 m2 of floor space. This note deals with the radiological considerations of operations using electrons up to 700 MeV and at power levels up to the safety envelope of 1 kW. Previous radiological considerations for electron and positron operations in the linac, PAR, and synchrotrons have been addressed else-where (MOE 93a, 93b, and 93c). Much of the methodology discussed in the previous writeups, as well as in MOE 94, has been used in the computations in this note. The radiological aspects that are addressed include the following: prompt secondary radiation (bremsstrahlung, giant resonance neutrons, medium- and high-energy neutrons) produced by electrons interacting in a beam stop or in component structures; skyshine radiation, which produces a radiation field in nearby areas and at the nearest off-site location; radioactive gases produced by neutron irradiation of air in the vicinity of a particle loss site; noxious gases (ozone and others) produced in air by the escaping bremsstrahlung radiation that results from absorbing particles in the components; activation of the LEUTL components that results in a residual radiation field in the vicinity of these materials following shutdown; potential activation of water used for cooling the magnets and other purposes in the tunnel; and evaluation of the

  16. A Comparative Numerical Study on the Performances and Vortical Patterns of Two Bioinspired Oscillatory Mechanisms: Undulating and Pure Heaving.

    Science.gov (United States)

    Ebrahimi, Mohsen; Abbaspour, Madjid

    2015-01-01

    The hydrodynamics and energetics of bioinspired oscillating mechanisms have received significant attentions by engineers and biologists to develop the underwater and air vehicles. Undulating and pure heaving (or plunging) motions are two significant mechanisms which are utilized in nature to provide propulsive, maneuvering, and stabilization forces. This study aims to elucidate and compare the propulsive vortical signature and performance of these two important natural mechanisms through a systematic numerical study. Navier-Stokes equations are solved, by a pressure-based finite volume method solver, in an arbitrary Lagrangian-Eulerian (ALE) framework domain containing a 2D NACA0012 foil moving with prescribed kinematics. Some of the important findings are (1) the thrust production of the heaving foil begins at lower St and has a greater growing slope with respect to the St; (2) the undulating mechanism has some limitations to produce high thrust forces; (3) the undulating foil shows a lower power consumption and higher efficiency; (4) changing the Reynolds number (Re) in a constant St affects the performance of the oscillations; and (5) there is a distinguishable appearance of leading edge vortices in the wake of the heaving foil without observable ones in the wake of the undulating foil, especially at higher St. PMID:27057133

  17. Observation and analysis of self-amplified spontaneous emission at the APS low-energy undulator test line

    CERN Document Server

    Arnold, N D; Banks, G; Bechtold, R; Beczek, K; Benson, C; Berg, S; Berg, W; Biedron, S G; Biggs, J A; Boerste, K; Borland, M; Bosek, M; Brzowski, W R; Budz, J; Carwardine, J A; Castro, P; Chae, Y C; Christensen, S; Clark, C; Conde, M; Crosbie, E A; Decker, G A; Dejus, Roger J; Deleon, H; Den Hartog, P K; Deriy, B N; Dohan, D; Dombrowski, P; Donkers, D; Doose, C L; Dortwegt, R J; Edwards, G A; Eidelman, Y; Erdmann, M J; Error, J J; Ferry, R; Flood, R; Forrestal, J; Freund, H; Friedsam, H; Gagliano, J; Gai, W; Galayda, J N; Gerig, R; Gilmore, R L; Gluskin, E; Goeppner, G A; Goetzen, J; Gold, C; Grelick, A E; Hahne, M W; Hanuska, S; Harkay, K C; Harris, G; Hillman, A L; Hogrefe, R; Hoyt, J; Huang, Z; Jagger, J M; Jansma, W G; Jaski, M; Jones, S J; Keane, R T; Kelly, A L; Keyser, C; Kim, K J; Kim, S H; Kirshenbaum, M; Klick, J H; Knoerzer, K; Knott, M; Koldenhoven, R J; Labuda, S; Laird, R; Lang, J; Lenkszus, F R; Lessner, E S; Lewellen, J W; Li, Y; Lill, R M; Lumpkin, Alex H; Makarov, O A; Markovich, G M; McDowell, M; McDowell, W P; McNamara, P E; Meier, T; Meyer, D; Michalek, W; Milton, S V; Moe, H; Moog, E; Morrison, L; Nassiri, A; Noonan, J R; Otto, R; Pace, J; Pasky, S J; Penicka, J M; Pietryla, A F; Pile, G; Pitts, C; Power, J; Powers, T; Putnam, C C; Puttkammer, A J; Reigle, D; Reigle, L; Ronzhin, D; Rotela, E R; Russell, E F; Sajaev, Vadim; Sarkar, S; Scapino, J C; Schröder, K; Seglem, R A; Sereno, N S; Sharma, S K; Sidarous, J F; Singh, O; Smith, T L; Soliday, R; Sprau, G A; Stein, S J; Stejskal, B; Svirtun, V; Teng, L C; Theres, E; Thompson, K; Tieman, B J; Torres, J A; Trakhtenberg, E; Travish, G; Trento, G F; Vacca, J; Vasserman, I B; Vinokurov, N A; Walters, D R; Wang, J; Wang, X J; Warren, J; Wesling, S; Weyer, D L; Wiemerslage, G; Wilhelmi, K; Wright, R; Wyncott, D; Xu, S; Yang, B X; Yoder, W; Zabel, R B

    2001-01-01

    Exponential growth of self-amplified spontaneous emission at 530 nm was first experimentally observed at the Advanced Photon Source low-energy undulator test line in December 1999. Since then, further detailed measurements and analysis of the results have been made. Here, we present the measurements and compare these with calculations based on measured electron beam properties and theoretical expectations.

  18. Evaluating the Fin-ray Trajectory Tracking of Bio-inspired Robotic Undulating Fins via an Experimental-numerical Approach

    Directory of Open Access Journals (Sweden)

    Xiaojia Xiang

    2014-07-01

    Full Text Available In the past decade, biomimetic undulating fin propulsion has been one of the main topics considered by scientists and researchers in the field of robotic fish. This technology is inspired by the biological wave-like propulsion of ribbon-finned fish. The swimming modes have aquatic application potentials with greater manoeuvrability, less detectable noise or wake and better efficiency at low speeds. The present work concentrates on the evaluation of fin-ray trajectory tracking of biorobotic undulating fins at the levels of kinematics and hydrodynamics by using an experimental-numerical approach. Firstly, fin-ray tracking inconsistence between the desired and actual undulating trajectories is embodied with experimental data of the fin prototype. Next, the dynamics' nonlinearity is numerically and analytically unveiled by using the computational fluid dynamics (CFD method, from the viewpoint of vortex shedding and the hydro-effect. The evaluation of fin-ray tracking performance creates a good basis for control design to improve the fin-ray undulation of prototypes.

  19. A table-top x-ray FEL based on a laser wakefield accelerator-undulator system

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, K.; Kawakubo, T.; Nakanishi, H. [National Lab. for High Energy Physics, Ibaraki-ken (Japan)] [and others

    1995-12-31

    Ultrahigh-gradient electron acceleration has been confirmed owing to the laser wakefield acceleration mechanism driven by an intense short laser wakefield acceleration mechanism driven by an intense short laser pulse in an underdense plasma. The laser wakefield acceleration makes it possible to build a compact electron linac capable of producing an ultra-short bunched electron beam. While the accelerator is attributed to longitudinal wakefields, transverse wakefields simultaneously generated by a short laser pulse can serve as a plasma undulator with a very short wavelength equal to a half of the plasma wavelength. We propose a new FEL concept for X-rays based on a laser wakefield accelerator-undulator system driven by intense short laser pulses delivered from table-top terawatt lasers. The system is composed of the accelerator stage and the undulator stage in a table-top size. A low energy electron beam is accelerated an bunched into microbunches due to laser wakefields in the accelerator stage. A micro-bunched beam travelling to the opposite direction of driving laser pulses produces coherent X-ray radiation in the undulator stage. A practical configuration and its analyses are presented.

  20. Coastline undulations on the West Coast of Denmark: Offshore extent, relation to breaker bars and transported sediment volume

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg; Fredsøe, Jørgen; Knudsen, Søren B.

    2012-01-01

    This paper deals with field measurements of undulations of the bottom bathymetry along an otherwise straight coast at the Danish West Coast. Two bathymetric datasets and two time series of wave measurements are used in order to determine the following properties: the offshore extent of shoreline ...

  1. Monoenergetic neutrino beam for long baseline experiments

    International Nuclear Information System (INIS)

    In an electron capture process by a nucleus, emitted neutrinos are monoenergetic. We study a long baseline experiment with such a completely monoenergetic neutrino beam. This talk is based on Refs. 1 and 2. (author)

  2. Breton Island, Louisiana Baseline (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Baseline (Geographic, NAD83) consists of vector line data that were input into the Digital Shoreline Analysis System (DSAS) version 4.0,...

  3. The potential for extending the spectral range accessible to the european X-ray free electron laser in the direction of longer wavelengths

    CERN Document Server

    Saldin, E L; Yurkov, M V

    2004-01-01

    The baseline specifications of European XFEL give a range of wavelengths between 0.1 nm and 2 nm. This wavelength range at fixed electron beam energy 17.5 GeV can be covered by operating the SASE FEL with three undulators which have different period and tunable gap. A study of the potential for the extending the spectral range accessible to the XFEL in the direction of longer wavelengths is presented. The extension of the wavelength range to 6 nm would be cover the water window in the VUV region, opening the facility to a new class of experiments. There are at least two possible sources of VUV radiation associated with the X-ray FEL; the "low (2.5 GeV) energy electron beam dedicated" and the " 17.5 GeV spent beam parasitic" (or "after-burner") source modes. The second alternative, "after-burner undulator" is the one we regard as most favorable. It is possible to place an undulator as long as 80 meters after 2 nm undulator. Ultimately, VUV undulator would be able to deliver output power approaching 100 GW. A b...

  4. Long-Baseline Neutrino Oscillation Experiments

    OpenAIRE

    Feldman, G J; Hartnell, J.; T. Kobayashi

    2013-01-01

    A review of accelerator long-baseline neutrino oscillation experiments is provided, including all experiments performed to date and the projected sensitivity of those currently in progress. Accelerator experiments have played a crucial role in the confirmation of the neutrino oscillation phenomenon and in precision measurements of the parameters. With a fixed baseline and detectors providing good energy resolution, precise measurements of the ratio of distance/energy (L/E) on the scale of ind...

  5. Towards an exact relativistic theory of Earth's geoid undulation

    Energy Technology Data Exchange (ETDEWEB)

    Kopeikin, Sergei M., E-mail: kopeikins@missouri.edu [Department of Physics & Astronomy, University of Missouri, Columbia, MO 65211 (United States); Siberian State Geodetic Academy, 10 Plakhotny St., Novosibirsk 630108 (Russian Federation); Mazurova, Elena M., E-mail: e_mazurova@mail.ru [Moscow State University of Geodesy and Cartography, 4 Gorokhovsky Alley, Moscow 105064 (Russian Federation); Siberian State Geodetic Academy, 10 Plakhotny St., Novosibirsk 630108 (Russian Federation); Karpik, Alexander P., E-mail: rector@ssga.ru [Siberian State Geodetic Academy, 10 Plakhotny St., Novosibirsk 630108 (Russian Federation)

    2015-08-14

    The present paper extends the Newtonian concept of the geoid in classic geodesy towards the realm of general relativity by utilizing the covariant geometric methods of the perturbation theory of curved manifolds. It yields a covariant definition of the anomalous (disturbing) gravity potential and formulates differential equation for it in the form of a covariant Laplace equation. The paper also derives the Bruns equation for calculation of geoid's height with full account for relativistic effects beyond the Newtonian approximation. A brief discussion of the relativistic Bruns formula is provided. - Highlights: • We apply general relativity to define the exact concept of relativistic geoid. • We derive relativistic equation of geoid and the reference level surface. • We employ the manifold perturbation theory to discuss geoid's undulation.

  6. Towards an exact relativistic theory of Earth's geoid undulation

    International Nuclear Information System (INIS)

    The present paper extends the Newtonian concept of the geoid in classic geodesy towards the realm of general relativity by utilizing the covariant geometric methods of the perturbation theory of curved manifolds. It yields a covariant definition of the anomalous (disturbing) gravity potential and formulates differential equation for it in the form of a covariant Laplace equation. The paper also derives the Bruns equation for calculation of geoid's height with full account for relativistic effects beyond the Newtonian approximation. A brief discussion of the relativistic Bruns formula is provided. - Highlights: • We apply general relativity to define the exact concept of relativistic geoid. • We derive relativistic equation of geoid and the reference level surface. • We employ the manifold perturbation theory to discuss geoid's undulation

  7. A Study on Inviscid Flow with a Free Surface over an Undulating Bottom

    Directory of Open Access Journals (Sweden)

    Srikumar Panda

    2016-01-01

    Full Text Available In this paper, the problem involving inviscid flow with a free surface over an undulating bottom is studied within the framework of linear theory. Applying perturbation analysis in conjunction with the Fourier transform technique, the boundary value problem arising from the flow problem is solved analytically. Behaviour of both interface and free-surface profiles, which are unknown at the outset, are analyzed. It is found that each profile (interface and free-surface possesses a wave free region at the far upstream, followed by a modulated downstream wave. It also observed, for the first time, that the amplitude of the downstream wave is varying. Further, the effects of various system parameters are analyzed and demonstrated in graphical forms.

  8. Cryogen-free magnetic field measurement setup for superconducting undulator coils

    International Nuclear Information System (INIS)

    The performance of superconducting insertion devices (IDs) depends strongly on the magnetic field quality. Precise measurements of magnetic properties are of fundamental importance for the characterization of IDs before installing in synchrotron light sources. Measurements of the field properties of conventional, i.e. permanent magnet based IDs have undergone tremendous improvements during the last years and initiated a new era in synchrotron light sources worldwide. A similar breakthrough is now necessary in the field of superconducting IDs. This is part of our R and D program for superconducting insertion devices to improve and perform quality management of their magnetic field properties. In this contribution we describe the setup for local and integral magnetic field measurements of superconducting undulator coils in a cold in vacuum (cryogen free) environment together with the results of the factory acceptance test of the measuring device.

  9. Cryogen-free magnetic field measurement setup for superconducting undulator coils

    Energy Technology Data Exchange (ETDEWEB)

    Grau, Andreas; Baumbach, Tilo; Casalbuoni, Sara; Gerstl, Stefan; Hagelstein, Michael; Holubek, Tomas; Saez de Jauregui, David [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany)

    2011-07-01

    The performance of superconducting insertion devices (IDs) depends strongly on the magnetic field quality. Precise measurements of magnetic properties are of fundamental importance for the characterization of IDs before installing in synchrotron light sources. Measurements of the field properties of conventional, i.e. permanent magnet based IDs have undergone tremendous improvements during the last years and initiated a new era in synchrotron light sources worldwide. A similar breakthrough is now necessary in the field of superconducting IDs. This is part of our R and D program for superconducting insertion devices to improve and perform quality management of their magnetic field properties. In this contribution we describe the setup for local and integral magnetic field measurements of superconducting undulator coils in a cold in vacuum (cryogen free) environment together with the results of the factory acceptance test of the measuring device.

  10. A water-cooled x-ray monochromator for using off-axis undulator beam

    International Nuclear Information System (INIS)

    Undulator beamlines at third-generation synchrotrons x-ray sources are designed to use the high-brilliance radiation that is contained in the central cone of the generated x-ray beams. The rest of the x-ray beam is often unused. Moreover, in some cases, such as in the zone-plate-based microfocusing beamlines, only a small part of the central radiation cone around the optical axis is used. In this paper, a side-station branch line at the Advanced Photon Source that takes advantage of some of the unused off-axis photons in a microfocusing x-ray beamline is described. Detailed information on the design and analysis of a high-heat-load water-cooled monochromator developed for this beamline is provided

  11. Cryogenic monochromator as a solution to undulator heat loads at third generation synchrotron sources

    International Nuclear Information System (INIS)

    We have developed a new design for a cryogenically cooled monochromator employing a thin-crystal strategy which is capable of handling the central-cone power of the Advanced Photon Source's Undulator A at closed gap and at the full design current of 300 mA. We have designed and fabricated a Si (111) crystal which has a thin section where the x-rays hit and has internal cooling channels. A invar manifold has also been designed and it will be attached to the Si via In gaskets. We have done detailed modeling, both with approximate analytical and with finite element calculations. The results shown that our design has negligible thermal strain even for closed gap operation

  12. A compact tunable polarized X-ray source based on laser-plasma helical undulators

    CERN Document Server

    Luo, Ji; Zeng, Ming; Vieira, Jorge; Yu, Lu-Le; Weng, Su-Ming; Silva, Luis O; Jaroszynski, Dino A; Sheng, Zheng-Ming; Zhang, Jie

    2016-01-01

    Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because their accelerating gradients are three orders of magnitude larger than traditional accelerators. However, X-ray radiation from such devices still lacks of tunability, especially the intensity and polarization distribution. Here we propose a tunable polarized radiation source from a helical plasma undulator based on plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of $2\\times10^{19} photons/s/mm^{2}/mrad^{2}/0.1%$ bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with the ...

  13. Basic Energy Sciences Synchrotron Radiation Center Undulator Sector at the Advanced Photon Source

    International Nuclear Information System (INIS)

    The Basic Energy Sciences Synchrotron Radiation Center (BESSRC) Collaborative Access Team (CAT) has designed and built a multipurpose undulator beamline at Sector 12 of the Advanced Photon Source (APS). The first optical enclosure contains all the white light components including a high performance thin, cryogenically cooled Si (1 1 1) double crystal monochromator. All the experimental stations are equipped with an exhaust for reactive gases that allows in-situ studies of chemical reactions. The monochromatic windowless beamline is used for elastic and inelastic X-ray scattering, surface scattering, small-angle scattering, and spectroscopy research. Each of these activities is in general confined to one of the three experimental stations. The end station (12-ID-D) is a monochromatic enclosure that is used for surface scattering and includes MOCVD equipment for in-situ measurements

  14. A new VUV high resolution undulator-based beamline at Super-ACO

    International Nuclear Information System (INIS)

    The VUV undulator-based high resolution SU5 beamline, designed to operate in the 5-45 eV photon energy range, is under construction at Super-ACO. It is composed of three toroidal mirrors around a 6.65 m Eagle off-plane normal incidence monochromator, whose induced-astigmatism is negligible owing to an horizontal focusing onto the gratings. With an optical design minimizing the aberrations and optimizing the throughput through the entrance slit, and with a careful choice of the optical coatings, the SU5 beamline should provide in the near future more than 1010 ph/s at the sample level for a 1/50000 bandwidth in the 5-25 eV energy range. The ultimate resolving power should be higher than 105. (orig.)

  15. Status of R and Ds for Undulators with Bulk High Temperature Superconductors

    International Nuclear Information System (INIS)

    Utilization of superconducting permanent magnets is now under investigation at SPring-8 for future development of synchrotron radiation sources, and several concepts has been reported so far. In one of them, ring-shaped bulk superconductors (ring SCs) will be used for enhancement of the undulator field strength. In the previous work, it was reported that the mechanical property of the ring SCs were so poor that the magnetic performance degraded during experiments. In this work, several methods are proposed to enhance the mechanical property of the ring SCs and results of experiments performed to investigate the effects of them are reported. Resin impregnation with a pole piece inserted into the ring SCs is found to be effective

  16. Investigation of X-ray induced radiation damage at the Si-SiO2 interface of silicon sensors for the European XFEL

    CERN Document Server

    Zhang, Jiaguo; Klanner, Robert; Pintilie, Ioana; Schwandt, Joern; Turcato, Monica

    2012-01-01

    Experiments at the European X-ray Free Electron Laser (XFEL) require silicon pixel sensors which can withstand X-ray doses up to 1 GGy. For the investigation of X-ray radiation damage up to these high doses, MOS capacitors and gate-controlled diodes built on high resistivity n-doped silicon with crystal orientations and produced by two vendors, CiS and Hamamatsu, have been irradiated with 12 keV X-rays at the DESY DORIS III synchrotron light source. Using capacitance/conductance-voltage, current-voltage and thermal dielectric relaxation current measurements, the surface densities of oxide charges and interface traps at the Si-SiO2 interface, and the surface-current densities have been determined as function of dose. Results indicate that the dose dependence of the surface density of oxide charges and the surface-current density depend on the crystal orientation and producer. In addition, the influence of the voltage applied to the gates of the MOS capacitor and the gate-controlled diode during X-ray irradia...

  17. Methods for calibrating the gain and offset of the DSSC detector for the European XFEL using X-ray line sources

    International Nuclear Information System (INIS)

    The DSSC (DEPFET Sensor with Signal Compression) will be a silicon based, 2d 1 Mpx imaging detector for the European X-ray Free Electron Laser Facility (XFEL.EU) in Hamburg, Germany. The DSSC is foreseen for soft X-radiation from 0.5 keV up to 6 keV . Driven by its scientific requirements, the design goals of the detector system are single photon detection, high dynamic range and a high frame rate of up to 4.5 MHz. Signal compression and amplification will be performed in the silicon sensor pixels yielding a low signal noise. Utilizing an in-pixel active filtering stage and an 8/9-bit ADC, the detector will provide parallel read-out of all pixels. In order to calibrate offset and gain, the procedure currently under investigation relies on determining peak positions in measurements with calibration line sources such as 55Fe. Here the status of studies of the stability and performance of a parameterized fit function designed for this task will be presented

  18. The European X-ray free-electron laser. Technical design report

    International Nuclear Information System (INIS)

    The following topics are dealt with: TTF/FLASH in the XFEL context, general layout of the XFEL facility, the XFEL accelerator, undulators for SAES and spontaneous emission, photon beamlines and scientific instruments, infrastructure and auxiliary systems, commissioning and operation, project management and organization, cost and time schedule. (HSI)

  19. The European X-ray free-electron laser. Technical design report

    Energy Technology Data Exchange (ETDEWEB)

    Altarelli, Massimo; Brinkmann, Reinhard; Chergui, Majed (and others)

    2007-07-15

    The following topics are dealt with: TTF/FLASH in the XFEL context, general layout of the XFEL facility, the XFEL accelerator, undulators for SAES and spontaneous emission, photon beamlines and scientific instruments, infrastructure and auxiliary systems, commissioning and operation, project management and organization, cost and time schedule. (HSI)

  20. Atmospheric media effects on ARIES baseline determination

    Science.gov (United States)

    Wu, S. C.

    1981-01-01

    Different types of media effects on ARIES baseline determination are compared. The effectiveness of simple ionospheric calibration models are studied. To perform the covariance analysis, an ARIES observation sequence needs to be assumed. For the current purposes, the observation sequence is selected to be that of experiment 80D over the JPL/Goldstone baseline (approximately 180 km). This experiment consisted of 96 observations over a period of approximately 25 hours on March 25 to 26, 1980. It is found through covariance analyses that the component most sensitive to media depends heavily upon the correlation, between the two stations, of the media effects. It is also found that relying on the cancellation of ionospheric delays between the two ray paths of VLBI observations at S band results in a large error in baseline length determination. High degree removal of ionospheric effects is possible with a crude model, providing correct diurnal peak and minimum ionospheric levels are input.

  1. Baseline methodologies for clean development mechanism projects

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.K. (ed.); Shrestha, R.M.; Sharma, S.; Timilsina, G.R.; Kumar, S.

    2005-11-15

    The Kyoto Protocol and the Clean Development Mechanism (CDM) came into force on 16th February 2005 with its ratification by Russia. The increasing momentum of this process is reflected in more than 100 projects having been submitted to the CDM Executive Board (CDM-EB) for approval of the baselines and monitoring methodologies, which is the first step in developing and implementing CDM projects. A CDM project should result in a net decrease of GHG emissions below any level that would have resulted from other activities implemented in the absence of that CDM project. The 'baseline' defines the GHG emissions of activities that would have been implemented in the absence of a CDM project. The baseline methodology is the process/algorithm for establishing that baseline. The baseline, along with the baseline methodology, are thus the most critical element of any CDM project towards meeting the important criteria of CDM, which are that a CDM should result in 'real, measurable, and long term benefits related to the mitigation of climate change'. This guidebook is produced within the frame work of the United Nations Environment Programme (UNEP) facilitated 'Capacity Development for the Clean Development Mechanism (CD4CDM)' Project. This document is published as part of the projects effort to develop guidebooks that cover important issues such as project finance, sustainability impacts, legal framework and institutional framework. These materials are aimed to help stakeholders better understand the CDM and are believed to eventually contribute to maximize the effect of the CDM in achieving the ultimate goal of UNFCCC and its Kyoto Protocol. This Guidebook should be read in conjunction with the information provided in the two other guidebooks entitled, 'Clean Development Mechanism: Introduction to the CDM' and 'CDM Information and Guidebook' developed under the CD4CDM project. (BA)

  2. Baseline methodologies for clean development mechanism projects

    International Nuclear Information System (INIS)

    The Kyoto Protocol and the Clean Development Mechanism (CDM) came into force on 16th February 2005 with its ratification by Russia. The increasing momentum of this process is reflected in more than 100 projects having been submitted to the CDM Executive Board (CDM-EB) for approval of the baselines and monitoring methodologies, which is the first step in developing and implementing CDM projects. A CDM project should result in a net decrease of GHG emissions below any level that would have resulted from other activities implemented in the absence of that CDM project. The 'baseline' defines the GHG emissions of activities that would have been implemented in the absence of a CDM project. The baseline methodology is the process/algorithm for establishing that baseline. The baseline, along with the baseline methodology, are thus the most critical element of any CDM project towards meeting the important criteria of CDM, which are that a CDM should result in 'real, measurable, and long term benefits related to the mitigation of climate change'. This guidebook is produced within the frame work of the United Nations Environment Programme (UNEP) facilitated 'Capacity Development for the Clean Development Mechanism (CD4CDM)' Project. This document is published as part of the projects effort to develop guidebooks that cover important issues such as project finance, sustainability impacts, legal framework and institutional framework. These materials are aimed to help stakeholders better understand the CDM and are believed to eventually contribute to maximize the effect of the CDM in achieving the ultimate goal of UNFCCC and its Kyoto Protocol. This Guidebook should be read in conjunction with the information provided in the two other guidebooks entitled, 'Clean Development Mechanism: Introduction to the CDM' and 'CDM Information and Guidebook' developed under the CD4CDM project. (BA)

  3. Investigation on the coherence of undulator source and soft X-ray interference lithography beamline in SSRF

    International Nuclear Information System (INIS)

    Background: Synchrotron radiation (SR) has some unique features such as higher brightness and continuously adjustable wavelength. Sometimes SR source will be a unique choice in some experiments. And with the development of the SR facility, especially the appearance of various low emittance undulators, the experiments such as coherent diffraction imaging (CDI) that needs high brightness coherence source can be conducted. The traditional ray trace software, such as Shadow, using the geometrical optics methods, could not be applied for the coherent beamlines. Purpose: We want to provide a basis for the beamline design and the X-ray coherent experiment, the effective evaluation of the spatial coherence in beamlines is needed. Undulator source, which can be calculated precisely, will become a plane source with some features. As the source of the beamline, undulator was calculated. And the spatial coherence of the exit slit can be calculated too. So we can analyze the coherence of the beamline. Methods: Firstly, we used BPM to measure the intensity of the diffraction of the slit, and simulated the intensity distribution of the slit diffraction using the MCI (a software written by ourselves) to confirm the coherent length of the secondary source at slit. Secondly, we calculated the undulator supposed as a plane source, and used the MCI to numerically calculate the propagation of partially coherent X-ray in the soft X-ray interference lithography beamline from the undulator to the exit slit. Finally, we compared the difference of the coherent length at the slit by the above two methods. Results: We calculated the coherent length at the different place in the beamline, such as mirrors and slits. The most important thing was that we could not only know the coherent length with different size of the slits, but also control the spatial coherence quantitatively. When the slit size was 40 μm×40 μm, the spatial coherence was almost fully coherent. And we used the method to do

  4. The Fermilab short-baseline neutrino program

    International Nuclear Information System (INIS)

    The Fermilab short-baseline program is a multi-facetted one. Primarily it searches for evidence of sterile neutrinos as hinted at by the MiniBooNE and LSND results. It will also measure a whole suite of ν-Argon cross sections which will be very useful in future liquid argon long-baseline projects. The program is based on MicroBooNE, already installed in the beam line, the recently approved LAr1-ND and the future addition of the refurbished ICARUS

  5. Waste management project technical baseline description

    Energy Technology Data Exchange (ETDEWEB)

    Sederburg, J.P.

    1997-08-13

    A systems engineering approach has been taken to describe the technical baseline under which the Waste Management Project is currently operating. The document contains a mission analysis, function analysis, requirement analysis, interface definitions, alternative analysis, system definition, documentation requirements, implementation definitions, and discussion of uncertainties facing the Project.

  6. National Cyberethics, Cybersafety, Cybersecurity Baseline Study

    Science.gov (United States)

    Education Digest: Essential Readings Condensed for Quick Review, 2009

    2009-01-01

    This article presents findings from a study that explores the nature of the Cyberethics, Cybersafety, and Cybersecurity (C3) educational awareness policies, initiatives, curriculum, and practices currently taking place in the U.S. public and private K-12 educational settings. The study establishes baseline data on C3 awareness, which can be used…

  7. Geochemical modelling baseline compositions of groundwater

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Kjøller, Claus; Andersen, Martin Søgaard;

    2008-01-01

    Reactive transport models, were developed to explore the evolution in groundwater chemistry along the flow path in three aquifers; the Triassic East Midland aquifer (UK), the Miocene aquifer at Valreas (F) and the Cretaceous aquifer near Aveiro (P). All three aquifers contain very old groundwaters...... of the evolution in natural baseline properties in groundwater....

  8. Solid Waste Program technical baseline description

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, A.B.

    1994-07-01

    The system engineering approach has been taken to describe the technical baseline under which the Solid Waste Program is currently operating. The document contains a mission analysis, function analysis, system definition, documentation requirements, facility and project bases, and uncertainties facing the program.

  9. The Geobiosphere Emergy Baseline: A synthesis

    Science.gov (United States)

    Following the Eighth Biennial Emergy Conference (January, 2014), the need for revisiting the procedures and assumptions used to compute the Geobiosphere Emergy Baseline (GEB) emerged as a necessity to strengthen the method of Emergy Accounting and remove sources of ambiguity and ...

  10. Waste management project technical baseline description

    International Nuclear Information System (INIS)

    A systems engineering approach has been taken to describe the technical baseline under which the Waste Management Project is currently operating. The document contains a mission analysis, function analysis, requirement analysis, interface definitions, alternative analysis, system definition, documentation requirements, implementation definitions, and discussion of uncertainties facing the Project

  11. Modified Daily Undulating Periodization Model Produces Greater Performance Than a Traditional Configuration in Powerlifters.

    Science.gov (United States)

    Zourdos, Michael C; Jo, Edward; Khamoui, Andy V; Lee, Sang-Rok; Park, Bong-Sup; Ormsbee, Michael J; Panton, Lynn B; Contreras, Robert J; Kim, Jeong-Su

    2016-03-01

    Zourdos, MC, Jo, E, Khamoui, AV, Lee, S-R, Park, B-S, Ormsbee, MJ, Panton, LB, Contreras, RJ, and Kim, J-S. Modified daily undulating periodization model produces greater performance than a traditional configuration in powerlifters. J Strength Cond Res 30(3): 784-791, 2016-The primary aim of this study was to compare 2 daily undulating periodization (DUP) models on one-repetition maximum (1RM) strength in the squat, bench press, deadlift, total volume (TV) lifted, and temporal hormone response. Eighteen male, college-aged (21.1 ± 1.9 years) powerlifters participated in this study and were assigned to one of 2 groups: (a) traditional DUP training with a weekly training order: hypertrophy-specific, strength-specific, and power-specific training (HSP, n = 9) or (b) modified DUP training with a weekly training order: hypertrophy-specific, power-specific, and strength-specific training (HPS, n = 9). Both groups trained 3 nonconsecutive days per week for 6 weeks and performed the squat, bench press, and deadlift exercises. During hypertrophy and power sessions, subjects performed a fixed number of sets and repetitions but performed repetitions until failure at a given percentage during strength sessions to compare TV. Testosterone and cortisol were measured at pretesting and posttesting and before each strength-specific day. Hypertrophy, power, and strength produced greater TV in squat and bench press (p ≤ 0.05) than HSP, but not for deadlift (p > 0.05). For squat and deadlift, there was no difference between groups for 1RM (p > 0.05); however, HPS exhibited greater increases in 1RM bench press than HSP (p ≤ 0.05). Effect sizes (ES) showed meaningful differences (ES > 0.50) in favor of HPS for squat and bench press 1RM. Testosterone decreased (p ≤ 0.05) at weeks 5 and 6 and cortisol decline at weeks 3 and 4. However, neither hormone was different at posttesting compared with pretesting (p > 0.05). Our findings suggest that an HPS configuration of DUP has enhanced

  12. High-field strong-focusing undulator designs for X-ray Linac Coherent Light Source (LCLS) applications

    International Nuclear Information System (INIS)

    Linac-driven X-Ray Free Electron Lasers (e.g., Linac Coherent Light Sources (LCLSs)), operating on the principle of single-pass saturation in the Self-Amplified Spontaneous Emission (SASE) regime typically require multi-GeV beam energies and undulator lengths in excess of tens of meters to attain sufficient gain in the 1 angstrom--0.1 angstrom range. In this parameter regime, the undulator structure must provide: (1) field amplitudes B0 in excess of 1T within periods of 4cm or less, (2) peak on-axis focusing gradients on the order of 30T/m, and (3) field quality in the 0.1%--0.3% range. In this paper the authors report on designs under consideration for a 4.5--1.5 angstrom LCLS based on superconducting (SC), hybrid/PM, and pulsed-Cu technologies

  13. Construction of the undulator beamline equipped with a UHV-STM for observations of synchrotron-radiation-stimulated surface reaction

    International Nuclear Information System (INIS)

    An undulator beamline equipped with a UHV-scanning tunneling electron microscopy (STM) system has been designed and constructed at the UVSOR facility to investigate synchrotron-radiation-stimulated reactions. Using this undulator beamline, we have observed irradiation effects on the hydrogen terminated-(H-) Si(1 1 1) surfaces in atomic scale. The small protrusions, which are assigned to the rest-atom with missing H, appeared on the monohydride surface after irradiation. The density of them monotonically increased with irradiation dose. This phenomenon has been observed almost independent on the Si 2p core electron excitation threshold, indicating the significant contribution of the valence electron excitations to the Si-H bond dissociations

  14. Procurement history of the hybrid undulator for the U-5 beam line at the national synchrotron light source

    International Nuclear Information System (INIS)

    As part of a national multi-institutional Materials Research Group (MRG), Argonne National Laboratory had the responsibility, under a prime contract with the US Department of Energy, of obtaining a Permanent Magnet Hybrid undulator to be used on the U5 Beam Line on the VUV Ring at the National Synchrotron Light Source (NSLS). The procurement involved determining the technical specifications of the device as well as developing an effective procedure for evaluation of the proposals. The conceptual-design of the magnetic structure including all pertinent magnetic field properties was developed before the actual procurement process was initiated. In addition, complete calculations of the expected spectral properties of the undulator were performed which included the emittance properties of the VUV ring. The results from both analysis were essential in determining the expected performance of the device and the final choice of operating parameters

  15. A method of determining narrow energy spread electron beams from a laser plasma wakefield accelerator using undulator radiation

    International Nuclear Information System (INIS)

    In this paper a new method of determining the energy spread of a relativistic electron beam from a laser-driven plasma wakefield accelerator by measuring radiation from an undulator is presented. This could be used to determine the beam characteristics of multi-GeV accelerators where conventional spectrometers are very large and cumbersome. Simultaneous measurement of the energy spectra of electrons from the wakefield accelerator in the 55-70 MeV range and the radiation spectra in the wavelength range of 700-900 nm of synchrotron radiation emitted from a 50 period undulator confirm a narrow energy spread for electrons accelerated over the dephasing distance where beam loading leads to energy compression. Measured energy spreads of less than 1% indicates the potential of using a wakefield accelerator as a driver of future compact and brilliant ultrashort pulse synchrotron sources and free-electron lasers that require high peak brightness beams.

  16. Analysis of a static undulation on the surface of a thin dielectric liquid layer formed by dielectrophoresis forces

    Science.gov (United States)

    Brown, Carl V.; McHale, Glen; Mottram, Nigel J.

    2011-07-01

    A layer of insulating liquid of dielectric constant ɛOil and average thickness h- coats a flat surface at y = 0 at which a one-dimensional sinusoidal potential V(x ,0)=VOcos(πx /p) is applied. Dielectrophoresis forces create a static undulation (or "wrinkle") distortion h(x) of period p at the liquid/air interface. Analytical expressions have been derived for the electrostatic energy and the interfacial energy associated with the surface undulation when h(x)=h--(1/2)Acos(2πx /p) yielding a scaling relationship for A as a function of h-, p, VO, ɛOil and the surface tension. The analysis is valid as A/p → 0, and in this limit convergence with numerical simulation of the system is shown.

  17. Thermo-mechanical analysis of the white-beam slits for an undulator beamline at the Advanced Photon Source

    International Nuclear Information System (INIS)

    A set of precision horizontal and vertical white-beam slits has been designed for an undulator beamline at the Advanced Photon Source. Due to the powerful x-ray heat flux emitted by the undulator, it is difficult to control the thermal distortion within the desired range of 1--2 μm. We analyzed many conceptual designs in an attempt to minimize the thermal distortion of the slits. Even with 1-mm-thick, low-Z material (graphite) coated on the heating surface of a traditional slit, the maximum thermal distortion is over 25 μm. A three-piece slit was then designed to satisfy the requirements. It consists of one large block, two tungsten knife edges, and an OFHC cooling tube (filled with copper mesh) brazed inside the large block. The thermal distortion at the knife edges of this three-piece slit is less than 2 μm

  18. Thermo-mechanical analysis of the white-beam slits for an undulator beamline at the Advanced Photon Source

    International Nuclear Information System (INIS)

    A set of precision horizontal and vertical white-beam slits has been designed for an undulator beamline at the Advanced Photon Source. Due to the powerful x-ray heat flux emitted by the undulator, it is difficult to control the thermal distortion within the desired range of 1-2 microns. We analyzed many conceptual designs in an attempt to minimize the thermal distortion of the slits. Even with 1-mm-thick, low-Z material (graphite) coated on the heating surface of a traditional slit, the maximum thermal distortion is over 25 microns. A three-piece slit was then designed to satisfy the requirements. It consists of one large block, two tungsten knife edges, and an OFHC cooling tube (filled with copper mesh) brazed inside the large block. The thermal distortion at the knife edges of this three-piece slit has a relative displacement of less than 2 microns

  19. Accelerated Best Basis Inventory Baselining Task

    International Nuclear Information System (INIS)

    The baselining effort was recently proposed to bring the Best-Basis Inventory (BBI) and Question No.8 of the Tank Interpretive Report (TIR) for all 177 tanks to the current standards and protocols and to prepare a TIR Question No.8 if one is not already available. This plan outlines the objectives and methodology of the accelerated BBI baselining task. BBI baselining meetings held during December 2000 resulted in a revised BBI methodology and an initial set of BBI creation rules to be used in the baselining effort. The objectives of the BBI baselining effort are to: (1) Provide inventories that are consistent with the revised BBI methodology and new BBI creation rules. (2) Split the total tank waste in each tank into six waste phases, as appropriate (Supernatant, saltcake solids, saltcake liquid, sludge solids, sludge liquid, and retained gas). In some tanks, the solids and liquid portions of the sludge and/or saltcake may be combined into a single sludge or saltcake phase. (3) Identify sampling events that are to be used for calculating the BBIs. (4) Update waste volumes for subsequent reconciliation with the Hanlon (2001) waste tank summary. (5) Implement new waste type templates. (6) Include any sample data that might have been unintentionally omitted in the previous BBI and remove any sample data that should not have been included. Sample data to be used in the BBI must be available on TWINS. (7) Ensure that an inventory value for each standard BBI analyte is provided for each waste component. Sample based inventories for supplemental BBI analytes will be included when available. (8) Provide new means and confidence interval reports if one is not already available and include uncertainties in reporting inventory values

  20. Mercury baseline levels in Flemish soils (Belgium)

    International Nuclear Information System (INIS)

    It is important to establish contaminant levels that are normally present in soils to provide baseline data for pollution studies. Mercury is a toxic element of concern. This study was aimed at assessing baseline mercury levels in soils in Flanders. In a previous study, mercury contents in soils in Oost-Vlaanderen were found to be significantly above levels reported elsewhere. For the current study, observations were extended over two more provinces, West-Vlaanderen and Antwerpen. Ranges of soil Hg contents were distinctly higher in the province Oost-Vlaanderen (interquartile range from 0.09 to 0.43 mg/kg) than in the other provinces (interquartile ranges from 0.7 to 0.13 and 0.7 to 0.15 mg/kg for West-Vlaanderen and Antwerpen, respectively). The standard threshold method was applied to separate soils containing baseline levels of Hg from the data. Baseline concentrations for Hg were characterised by a median of 0.10 mg Hg/kg dry soil, an interquartile range from 0.07 to 0.14 mg/kg and a 90% percentile value of 0.30 mg/kg. The influence of soil properties such as clay and organic carbon contents, and pH on baseline Hg concentrations was not important. Maps of the spatial distribution of Hg levels showed that the province Oost-Vlaanderen exhibited zones with systematically higher Hg soil contents. This may be related to the former presence of many small-scale industries employing mercury in that region. - Increased mercury levels may reflect human activity

  1. Magnetic field calculation of variably polarizing undulator (APPLE-type) for SX beamline in the SPring-8

    International Nuclear Information System (INIS)

    This paper describes the design of a variably polarizing undulator (APPLE-type) to be installed in soft X-ray beamline in the SPring-8 facility. The magnetic field distribution and radiation spectrum expected from this undulator were calculated. The magnetic field strength is varied by changing the gap distance of upper and lower jaws, so it changes the photon energy in soft X-ray range. By moving the relative position of pairs of magnet rows (phase shift), the polarization of radiation is varied circularly, elliptically and linearly in the horizontal and vertical direction. We expect that right and left handed circular polarizations are obtained alternately at a rate of 1 Hz by high speed phase shifting. The repulsive and attractive magnetic force working on the magnet rows were calculated which interfere in phase shifting at high speed. The magnetic force changes with gap distance and phase shift position, and the magnetic force working on a row in the direction of phase shift becomes up to 500 kgf. The construction of this undulator is started in 1996, that will be inserted in the storage ring in 1997. (author)

  2. Surface-micromachined magnetic undulator with period length between 10μm and 1 mm for advanced light sources

    Science.gov (United States)

    Harrison, Jere; Joshi, Abhijeet; Lake, Jonathan; Candler, Rob; Musumeci, Pietro

    2012-07-01

    A technological gap exists between the μm-scale wiggling periods achieved using electromagnetic waves of high intensity laser pulses and the mm scale of permanent-magnet and superconducting undulators. In the sub-mm range, surface-micromachined soft-magnetic micro-electro-mechanical system inductors with integrated solenoidal coils have already experimentally demonstrated 100 to 500 mT field amplitude across air gaps as large as 15μm. Simulations indicate that magnetic fields as large as 1.5 T across 50μm inductor gaps are feasible. A simple rearranging of the yoke and pole geometry allows for fabrication of 10+ cm long undulator structures with period lengths between 12.5μm and 1 mm. Such undulators find application both in high average power spontaneous emission sources and, if used in combination with ultrahigh-brightness electron beams, could lead to the realization of low energy compact free-electron lasers. Challenges include electron energy broadening due to wakefields and Joule heating in the electromagnet.

  3. Downsizing of Johansson spectrometer for X-ray fluorescence trace analysis with brilliant undulator source

    International Nuclear Information System (INIS)

    The downsizing of a Johansson-type X-ray fluorescence (XRF) spectrometer has been examined as a way of enhancing detection efficiency with a tolerable loss of energy resolution. A compact spectrometer equipped with a Ge(2 2 0) analyzing crystal with a Rowland radius of 120 mm has been tested with a highly brilliant helical undulator source at BL40XU, SPring-8. The energy resolution obtained for cobalt Kα1 (6930.32 eV) was 8.8 eV, which is 10-20 times better than that obtained using a Si(Li) detector, and effectively improved the signal-to-background ratio for XRF spectra. The combination of the present spectrometer and a third generation synchrotron source could provide new opportunities for trace analytical applications, which have been difficult so far by conventional synchrotron XRF experiments based on a Si(Li) detector system. The detection limit obtained for solid bulk samples has reached a level of several tens of ppb

  4. Undulator for the LCLS Project Changes in the Magnet Structure Design

    CERN Document Server

    Trakhtenberg, Emil; Powers, Thomas

    2005-01-01

    The design modifications of a new hybrid-type undulator with a fixed gap of 6.4 mm, a period of 30 mm and a length of 3.4 m are presented. The prior pole design included side "wings" which were used for precise positioning, and clamps to fasten poles to the magnet base. This design has been replaced by a more straightforward assembly, where the pole is attached to the magnet structure base using only two screws. Tests were performed on the vanadium permendure pole material to prove that the threaded holes are easy to fabricate and are able to successfully withstand the torque required to hold the pole in place. A fixture was also developed to ensure the precise location of the poles on the base during assembly. In addition to the pole modifications, the magnet structure base is now manufactured as one piece as opposed to three, which greatly eases assembly. Finally, a small section of the original prototype had these changes successfully implemented, and the test results are presented.

  5. Undulator for the LCLS project - changes in the magnet structure design

    International Nuclear Information System (INIS)

    The design modifications of a new hybrid-type undulator with a fixed gap of 6.8 mm, a period of 30 mm and a length of 3.4 m are presented. The prior pole design included side 'wings, s' which were used for precise positioning, and clamps to fasten the poles to the magnet base. This design has been replaced by a more straightforward assembly, where the pole is attached to the magnet structure base using only two screws. Tests were performed on the vanadium permendur pole material to prove that the threaded holes are easy to fabricate and are able to successfully withstand the torque required to hold the pole in place. A fixture was also developed to ensure the precise location of the poles on the base during assembly. In addition to the pole modifications, the magnet-structure base is now manufactured as one piece as opposed to three, which greatly eases assembly. Finally, a small section of the original prototype had these changes successfully implemented, and the test results are presented

  6. Hydraulic Transients Caused by Air Expulsion During Rapid Filling of Undulating Pipelines

    Directory of Open Access Journals (Sweden)

    Ciro Apollonio

    2016-01-01

    Full Text Available One of the main issues arising during the rapid filling of a pipeline is the pressure transient which originates after the entrapped air has been expelled at the air release valve. Because of the difference in density between water and air, a pressure transient originates at the impact of the water column. Many authors have analyzed the problem, both from the theoretical and the experimental standpoint. Nevertheless, mainly vertical or horizontal pipelines have been analyzed, whereas in real field applications, the pipe profile is a sequence of ascending and descending pipes, with air release/vacuum valves at high points. To overcome lack of knowledge regarding this latter case, laboratory experiments were carried out to simulate the filling of an undulating pipeline, initially empty at atmospheric pressure. The pipe profile has a high point where an orifice is installed for air venting, so as to simulate the air release valve at intermediate high point of a supply pipeline. In the experiments, the diameter of the orifice and the opening degree of both upstream and downstream valves were varied, in order to analyze their effect on the pressure transient. The experiments were also carried out with a longer descending pipe, in order to assess the effects on the pressure surge of the air volume downstream of the orifice.

  7. Reynolds averaged theory of turbulent shear flows over undulating beds and formation of sand waves.

    Science.gov (United States)

    Bose, Sujit K; Dey, Subhasish

    2009-09-01

    Based on the Reynolds averaged Navier-Stokes (RANS) equations and the time-averaged continuity equation, a theory of turbulent shear flow over an undulating sand bed is developed addressing the instability criterion of plane sand beds in free-surface flows leading to the formation of sand waves. In the analysis, the integration of RANS equations leads to generalized Saint Venant equations, in which the time-averaged streamwise velocity is characterized by a power law obtained from turbulence closure, treating the curvilinear streamlines by the Boussinesq approximation. As a consequence, the modified pressure distribution has a departure from the traditionally linear hydrostatic pressure distribution. The instability analysis of a plane sand bed yields the curves of the Froude number versus nondimensional wave number, determining an instability zone for which at lower Froude numbers (less than 0.8), the plane bed becomes unstable with the formation of dunes; whereas at higher Froude numbers, the plane bed becomes unstable with the formation of standing waves and antidunes. For higher Froude numbers, the experimental data for antidunes lie within the unstable zone; while for lower Froude numbers, the same is found for dunes with some experimental scatter. PMID:19905209

  8. Analysis of electro-osmotic flow in a microchannel with undulated surfaces

    CERN Document Server

    Yoshida, Hiroaki; Washizu, Hitoshi

    2016-01-01

    The electro-osmotic flow through a channel between two undulated surfaces induced by an external electric field is investigated. The gap of the channel is very small and comparable to the thickness of the electrical double layers. A lattice Boltzmann simulation is carried out on the model consisting of the Poisson equation for electrical potential, the Nernst--Planck equation for ion concentration, and the Navier--Stokes {\\color{black}equations} for flows of the electrolyte solution. An analytical model that predicts the flow rate is also derived under the assumption that the channel width is very small compared with the characteristic length of the variation along the channel. The analytical results are compared with the numerical results obtained by using the lattice Boltzmann method. In the case of a constant surface charge density along the channel, the variation of the channel width reduces the electro-osmotic flow, and the flow rate is smaller than that of a straight channel. In the case of a surface ch...

  9. Development of Compact Soft X-ray Source Based on Laser Undulator

    CERN Document Server

    Kuroda, Ryunosuke; Minamiguchi, S; Saitô, T; Ueyama, D; Washio, Masakazu

    2004-01-01

    A compact soft X-ray source is required in various research fields such as material and biological science. The laser undulator based on backward Compton scattering has been developed as a compact soft X-ray source for the biological observation at Waseda University. It is performed in a water window region (250eV - 500 eV) using the interaction between 1047 nm Nd:YLF laser and 4 MeV high quality electron beam generated from rf gun system. The range of energy in the water window region has K-shell absorption edges of Oxygen, Carbon and Nitrogen, which mainly constitute of living body. Since the absorption coefficient of water is much smaller than the protein’s coefficient in this range, a dehydration of the specimens is not necessary. As a preliminary experiment, about 300 eV X-ray generation was carried out. As next step, soft X-ray optics with zone plate was proposed for Soft X-ray microscopy. In this conference, we will report details and results of the experiment.

  10. Scapaundulin C, a novel labdane diterpenoid isolated from Chinese liverwort Scapania undulate, inhibits acetylcholinesterase activity.

    Science.gov (United States)

    Kang, Ya-Qi; Zhou, Jin-Chuan; Fan, Pei-Hong; Wang, Shu-Qi; Lou, Hong-Xiang

    2015-12-01

    In the present study, scapaundulin C (1), a new labdane diterpenoid, and four related known compounds scapaundulin A (2), 5α, 8α, 9α-trihydroxy-13E-labden-12-one (3), 5α, 8α-dihydroxy-13E-labden-12-one (4), and (13S)-15-hydroxylabd-8 (17)-en-19-oic acid (5), were isolated from the Chinese liverwort Scapania undulate (L.) Dum., using column chromatography. The structures of these compounds were determined on the basis of 1D- and 2D-NMR analyses. The acetylcholinesterase (AchE) inhibitory activity was evaluated using a bioautographic TLC assay and the cytotoxic activity was evaluated by the MTT method. All the compounds were reported for the first time to exhibit moderate AchE inhibitory activity with minimal inhibitory quantities ranging from 250 to 500 ng. All the compounds were tested for their cytotoxicity against five human tumor cell lines, A549, K562, A2780, Hela, and HT29, and compounds 3 and 4 exhibited moderate inhibitory effects on the growth of A2780 cells. PMID:26721712

  11. Surface undulations of Antarctic ice streams tightly controlled by bedrock topography

    Directory of Open Access Journals (Sweden)

    J. De Rydt

    2012-10-01

    Full Text Available Full Stokes models predict that fast-flowing ice streams transmit information about their bedrock topography most efficiently to the surface for basal undulations with length scales between 1 and 20 times the mean ice thickness. This typical behaviour is independent on the precise values of the flow law and sliding law exponents, and should be universally observable. However, no experimental evidence for this important theoretical prediction has been obtained so far, hence ignoring an important test for the physical validity of current-day ice flow models. In our work we use recently acquired airborne radar data for the Rutford Ice Stream and Evans Ice Stream, and we show that the surface response of fast-flowing ice is highly sensitive to bedrock irregularities with wavelengths of several ice thicknesses. The sensitivity depends on the slip ratio, i.e. the ratio between mean basal sliding velocity and mean deformational velocity. We find that higher values of the slip ratio generally lead to a more efficient transfer, whereas the transfer is significantly dampened for ice that attains most of its surface velocity by creep. Our findings underline the importance of bedrock topography for ice stream dynamics on spatial scales up to 20 times the mean ice thickness. Our results also suggest that local variations in the flow regime and surface topography at this spatial scale cannot be explained by variations in basal slipperiness.

  12. X-Ray microprobe characterization of materials: the case for undulators on advanced storage rings

    International Nuclear Information System (INIS)

    The unique properties of X-rays offer many advantages over electrons and other charged particles for the microcharacterization of materials. X-rays are more efficient in exciting characteristic X-ray fluorescence and produce higher fluorescent signals to backgrounds than obtained with electrons. Detectable limits for X-rays are a few parts per billion and are 10-3 to 10-5 less than obtained with electrons. Energy deposition in the sample by X-rays is 10-3 to 10-4 less than for electrons for the same detectable concentration. High-brightness storage rings, especially in the 6 GeV class with undulators, will be approximately 103 brighter in the X-ray energy range from 5 keV to 35 keV than existing storage rings and provide for X-ray microprobes that are as bright as the most advanced electron probes. Such X-ray microprobes will produce unprecedented low levels of detection in diffraction, EXAFS, Auger, and photoelectron spectoscopies for both chemical characterization and elemental identification. These major improvements in microcharacterization capabilities will be wide-ranging ramifications not only in materials science but also in physics, chemistry, geochemistry, biology, and medicine

  13. The U5.0 undulator design for the advanced light source at LBL

    International Nuclear Information System (INIS)

    The U5.0 undulator, currently under design, is the first in a series of insertion devices planned for the Advanced Light Source at LBL. U5.0 parameters include a 5 cm period, 5 m length with a 0.837 T maximum field at a 14 mm gap. A hybrid configuration utilizing Nd-Fe-B permanent magnet material and Vanadium Permendur poles is used for the magnetic structure. Construction is modular with many pole assemblies attached to a pole mount, which in turn is fastened onto one of the backing beams. Vertical field integral correction at the ends is with permanent magnet rotators. The supports structure features a 4-post configuration, a rigid base with 3 kinematic floor supports and 2 rigid 5 m long backing beams that fit within the 2.4 m high accelerator enclosure. The drive system is computer controlled utilizing a stepper motor and shaft encode coupled to a roller-screw/nut and chain drive train. Vacuum chamber design is a rigid configuration with a 10 mm vertical by 218 mm horizontal aperture of 5.5 m length. Chamber fabrication features a two-piece welded chamber of 5083 H321 aluminum. Pumping is with ion and titanium sublimation pumps. 5 figs., 1 tab

  14. X-ray microprobe characterization of materials: the case for undulators on advanced storage rings

    International Nuclear Information System (INIS)

    The unique properties of X rays offer many advantages over electrons and other charged particles for the microcharacterization of materials. X rays are more efficient in exciting characteristic X-ray fluorescence and produce higher fluorescent signals to backgrounds than obtained with electrons. Detectable limits for X rays are a few parts per billion and are 10-3 to 10-5 less than for electrons. Energy deposition in the sample by X rays is 10-3 to 10-4 less than for electrons for the same detectable concentration. High-brightness storage rings, especially in the 6 GeV class with undulators, will be approximately 103 brighter in the X-ray energy range from 5 keV to 35 keV than existing storage rings and provide for X-ray microprobes that are as bright as the most advanced electron probes. Such X-ray microprobes will produce unprecedented low levels of detection in diffraction, EXAFS, Auger, and photoelectron spectroscopies for both chemical characterization and elemental identification. These major improvements in microcharacterization capabilities will have wide-ranging ramifications not only in materials science but also in physics, chemistry, geochemistry, biology, and medicine

  15. On the calibration of large-scale fluorometric chlorophyll measurements from towed undulating vehicles

    Science.gov (United States)

    Strass, Volker

    1990-03-01

    Calibrating in situ fluorescence profiles to give the concentration of chlorophyll a at high resolution on the oceanic gyre scale must take into account large variations of fluorescence yield R (the ratio of the fluorescence signal and the chlorophyll concentration within the fluorometer detection volume). The calibration method suggested in this paper has been developed to handle fluorescence measurements made from a towed undulating vehicle along a section about 2000 km long between the Azores and Greenland repeated during the years 1984-1986. The calibration is based on equally spaced samples with photometrically determined near-surface chlorophyll concentrations and incorporates profiles of solar irradiance as auxillary variable. Judging from the auto-correlation function of R, the large variations of fluorescence yield are well resolved by the time interval of 4 h (corresponding to a horizontal distance of about 65 km) between adjacent chlorophyll samples. Using a filter based on the auto-correlation function the variability of yield is smoothed; the smoothed yield function is employed to calibrate the fluoresence signal continuously, in which yield between supporting points is interpreted linearly. Significant correlations of R with solar irradiance appear to be negative; this ambient-light-dependent fluorescence quenching is eliminated during calibration. The relative error in the chlorophyll concentration derived in this way is estimated to be 4% near the surface and 15% deeper down. The suggested calibration method is as accurate as more expensive procedures involving bottle cast series.

  16. Fiber diffraction using the BioCAT undulator beamline at the Advanced Photon Source

    CERN Document Server

    Irving, T C; Rosenbaum, G; Bunker, G B

    2000-01-01

    The BioCAT undulator-based beamline at the Advanced Photon Source, Argonne IL, USA is designed to be a state-of-the-art instrument for biological non-crystalline diffraction and X-ray absorption spectroscopy. The optics consist of double crystal monochromators with sagitally focussing second crystals followed by a vertically focussing mirror which allow independent focussing of the beam in the vertical and horizontal directions virtually anywhere along the length of the 12 m experimental enclosure. When configured for a 2 m fiber diffraction camera, a focal spot of less than 40x200 mu m (FWHM) has been observed which contained essentially all of the 1.5-2.5x10 sup 1 sup 3 ph/s delivered by the cryogenically-cooled Si(1 1 1) double crystal monochromator. This combination of highly demagnifying optics and the very low divergence of the very small source have yielded excellent quality patterns from various muscle specimens and collagen-containing tissues. Detectors available include a Fuji BAS2500 image plate sc...

  17. Present status of laser undulator compact X-ray source (LUCX) (7)

    International Nuclear Information System (INIS)

    We have developed a compact X-ray source via inverse Compton scattering between a multi-bunch electron beam and a laser pulse stacked in an optical cavity at Laser Undulator Compact X-ray (LUCX) accelerator in KEK. Our aim is to obtain a clear X-ray image in a shorter period of times in this accelerator, which consists of a 3.6 cell photo-cathode rf-gun, a 12cell standing wave accelerating structure and a 4-mirror planar optical cavity. In 2012, we have upgraded the accelerator to increase the intensity of X-ray. The expected number of X-ray after upgrade is 1.7x107 photons/pulse with 10% bandwidth. To achieve this target, it is necessary to increase the intensity of an electron beam to 500nC/pulse with 1000 bunches at 30 MeV. We have continued the multi-bunch beam generation and X-ray imaging test after upgrade. The accelerator produces 24 MeV beam with the total charge of 460nC in 800 bunches per pulse now. The aging process is also continued to increase energy and intensity. In this paper, the present status and the results of beam tuning and X-ray generation of LUCX accelerator will be reported. (author)

  18. Present status of laser undulator compact X-ray source (LUCX) (6)

    International Nuclear Information System (INIS)

    We have developed a compact X-ray source via inverse Compton scattering between multi-bunch electron beam and a laser pulse stacked in an optical cavity at Laser Undulator Compact X-ray (LUCX) accelerator in KEK. Since the autumn of 2011, we have begun X-ray imaging test. In the beginning, it had taken two hours to get an X-ray image because of low intensity of X-ray with 104 photons/pulse. To obtain a clear X-ray image in a shorter period of times, we have upgraded the accelerator, which consists of a 3.6 cell photo-cathode rf-gun, a 12 cell standing wave accelerating structure and a 4-mirror planar optical cavity. The expected number of X-ray after upgrade is 1.7x107 photons/pulse with 10% bandwidth. To achieve this target, it is necessary to increase the intensity of an electron beam to 500nC/pulse with 1000 bunches at 30 MeV. We have already started the multi-bunch beam generation and X-ray imaging test after upgrade. The accelerator produces 24 MeV beam with the total charge of 380nC in 300 bunches per pulse now. The aging process is also continued to increase energy and intensity. In this paper, the present status and the results of beam tuning of LUCX accelerator will be reported. (author)

  19. Joint Multi-baseline SAR Interferometry

    Directory of Open Access Journals (Sweden)

    S. Tebaldini

    2005-12-01

    Full Text Available We propose a technique to provide interferometry by combining multiple images of the same area. This technique differs from the multi-baseline approach in literature as (a it exploits all the images simultaneously, (b it performs a spectral shift preprocessing to remove most of the decorrelation, and (c it exploits distributed targets. The technique is mainly intended for DEM generation at centimetric accuracy, as well as for differential interferometry. The problem is framed in the contest of single-input multiple-output (SIMO channel estimation via the cross-relations (CR technique and the resulting algorithm provides significant improvements with respect to conventional approaches based either on independent analysis of single interferograms or multi-baselines phase analysis of single pixels of current literature, for those targets that are correlated in all the images, like for long-term coherent areas, or for acquisitions taken with a short revisit time (as those gathered with future satellite constellations.

  20. Multiple position borehole extensometer baseline algorithm

    International Nuclear Information System (INIS)

    This document provides the baseline algorithm for the Multiple Position Borehole Extensometers (MPBX's) used at the Near-Surface Test Facility (NSTF) as a part of the Rock Instrumentation System (RIS) for Full Scale Heater Tests (FS) number-sign 1 and number-sign 2. It represents the baseline information available at the time of publication. The purpose of this document is to state the algorithm to be used for the MPBX's at the NSTF, the basis for the equations, the method used to arrive at the constants in the equations, and to identify further instrument testing necessary to improve the understanding of the instrument's purpose in this high temperature, hard rock environment. 5 refs., 5 figs