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| MOP020 | Compact Spectrometer for Single Shot X-ray Emission and Photon Diagnostics | photon, FEL, target, diagnostics | 62 |
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| The design and characterization of a compact spectrometer realized for photon in-photon out experiments (in particular X-Ray Emission Spectroscopy), conceived to be used at the FERMI free-electron-laser (FEL) at ELETTRA (Italy) is here presented. The instrument can be easily installed on different end stations at variable distances from the target area both at synchrotron and FEL beamlines. Different input sections can be accommodated in order to fit the experimental requests. The design is compact in order to realize a portable instrument within an overall size of less than one square meter. The spectrometer covers the 25-800 eV spectral range, with spectral resolution better than 0.2%. The characterization on Gas Phase @ ELETTRA as instrument for XES and some experimental data of the FEL emission acquired at EIS-TIMEX @ FERMI, where the instrument has been used for photon beam diagnostics, are introduced. | |||
| MOP023 | Development of a Magnetic System to Cancel the Attractive Force toward Structural Reform of Undulators | undulator, multipole, experiment, vacuum | 75 |
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| As part of a development on a compact and lightweight structure toward structural reform of undulators, cancellation of magnetic attractive force is being studied. Undulators usually require rigid mechanical components and frames to control the magnet gap precisely against the large attractive force in between. If the attractive force is canceled out near the point of load, the requirement for the undulator structure is relaxed and the cost and lead time of construction and installation are saved largely. For that purpose, we have proposed to add periodically-magnetized monolithic magnets beside the main magnets, which are expected to generate a repulsive force having the same gap-dependency as the attractive force in a cost-effective way. In the conference, the present status of the development of the force cancellation system will be presented, with a focus on the result of preliminary experiments using the periodically-magnetized magnets. Also introduced will be a development plan for the compact and lightweight undulator based on the cancellation system. | |||
| MOP084 | Enhancing Coherent Harmonic Generation using Tilted Laser Wavefronts | laser, electron, radiation, synchrotron-radiation | 248 |
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Funding: Work supported by BMBF (contract 05K13PE3) Coherent Harmonic Generation (CHG) to produce ultrashort pulses of synchrotron radiation is based on the interaction of relativistic electrons in a storage ring with femtosecond laser pulses in an undulator. The resulting periodic energy modulation can be converted to a density modulation by a dispersive chicane, giving rise to coherent emission at harmonics of the laser wavelength in a second undulator. If the first undulator is in a section with non-zero dispersion, the density modulation can be enhanced using tilted laser wavefronts, thus delaying the phase-space distributions of electrons with different energy with respect to each other. The most simple way to realize the wavefront tilt would be to introduce a small crossing angle between the electron and laser beam. Details are discussed for the case of the CHG short-pulse facility at DELTA, a 1.5-GeV synchrotron light source at the TU Dortmund University, but HGHG and EEHG seeding of free-electron lasers could also be performed this way. |
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| TUP023 | Modeling CSR in a Vacuum Chamber by Partial Fourier Analysis and the Discontinuous Galerkin Method | synchrotron-radiation, impedance, radiation, vacuum | 419 |
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Funding: Work supported by DOE contracts DE-FG-99ER41104 and DE-AC03-76SF00515. We continue our study of CSR* from a bunch on an arbitrary curved orbit in a plane, which used a Fourier transform in s-ct. The vacuum chamber has rectangular cross section with possibly varying horizontal width. We use the slowly varying amplitude approximation, and invoke a Fourier expansion in the vertical coordinate y, which meets the boundary conditions on the top and bottom plates and makes contact with the Bessel equation of the frequency domain treatment. The fields are defined by a PDE in s and x, first order in s, which is discretized in x by finite differences (FD) or the discontinuous Galerkin method (DG). We compare results of FD and DG, and also compare to our earlier calculations in 3D (paraxial) which did not use the Fourier series in y*,**. This approach provides more transparency in the physical description, and when only a few y-modes are needed, provides a large reduction in computation time. * See FEL13 Proceedings MOPSO06: http://accelconf.web.cern.ch/AccelConf/FEL2013/papers/mopso06.pdf ** See PRST-AB 7 054403 (2004) and Jpn. J. Appl. Phys. 51 016401 (2012). |
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| TUP077 | Characteristics of Transported Terahertz-wave Coherent Synchrotron Radiation at LEBRA | FEL, electron, radiation, synchrotron-radiation | 541 |
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Funding: This work has been supported in part under the Visiting Researcher's Program of the Research Reactor Institute, Kyoto University, and ZE Research Program ZE25B-7, Kyoto University. Nihon University and National Institute of Advanced Industrial Science and Technology have jointly developed terahertz-wave coherent synchrotron radiation (CSR) at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University since 2011. We have already observed intense terahertz-wave radiation from a bending magnet located above an undulator dedicated for an infrared free-electron laser (FEL), and confirmed it to be CSR [*]. Moreover, we have transported the CSR to an experimental room, which is next to the accelerator room across a shield wall, using an infrared FEL beamline. The transported CSR beam can be applied to two-dimensional imaging and spectroscopy experiments. In this presentation, characteristics of the CSR beam and applications for the CSR beam at LEBRA will be reported. * N. Sei et al., “Observation of intense terahertz-wave coherent synchrotron radiation at LEBRA”, J. Phys. D, 46 (2013) 045104. |
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