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Showing 1 to 18 of 18 for “"undulator"”.
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Novel designs for undulator based positron sources
… designs have been proposed. One of these is an undulator-based positron source, which is the baseline positron source design for the International Linear Collider. The undulator-based positron source for the International Linear Collider uses a helical undulator to produce a intense photon beam …
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Beam-Induced Radiation Heating on the Superconducting Undulator at the Advanced Photon Source
… X-ray source, commissioned a Superconducting Undulator (SCU). The superconducting magnet is thermally isolated from the beam vacuum chamber, which absorbs the beam-induced heating. Previous beam induced heat load studies at other laboratories had not included a robust calculation of radiation …
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An ultra-high resolution pulsed-wire magnet measurement system
… part on the quality of the magnetic field in the undulator. Ideally the magnetic field on the axis of the undulator is transverse to the axis and sinusoidally varying due to the periodic sequence of alternating field dipole magnets. The resulting ideal trajectory of a relativistic electron bunch …
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Towards a free-electron laser driven by a laser wakefield accelerator
… Efficient electron beam transport through an undulator (100 periods, period = 15 mm) is demonstrated implying an estimated source diameter of 300 μm close to the centre of the undulator (in agreement with simulation). Undulator radiation have been generated using electron beams of energy …
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Free-electron-driven nanoscale light sources: from Hertzian antennas to metamaterials
… degree of complexity: a nanoscale antenna, an undulator-based tuneable nanoscale light source and a metamaterial-based spatially coherent light source. I have demonstrated for the first time that a nanoscale Hertzian antenna can be driven by free-electrons. The studied nano-antennas consisting …
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Novel techniques in free electron lasers
… when matched to amplification profile of an undulatorchicane lattice generates a train of coherent radiation spikes. The interaction of multiple electron pulses is investigated in this thesis. Propagating multiple electron pulses through an undulator produce a train of radiation spikes. The …
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Studies in positron and gamma ray production for future facilities
… trajectories of electrons passing through the undulator. I present an investigation of using the spent gamma ray beam of the ILC for additional applications, including nuclear physics. As a result of changing the collimator shape, as well as the parameters of the undulator magnets, I obtain …
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Simulation and design methods for free-electron laser systems
… wave and pendulum equations, and the concepts of undulator taper, extraction and beam quality. Two computer programs used for FEL simulation (FEL3D/FEL4D, developed at the Naval Postgraduate School, and Ginger, developed at Lawrence Berkeley National Laboratory) are discussed and compared, then …
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Timing Diagnostics and Coherent Harmonics from a test-FEL
… were extracted in an APPLE-II type elliptical undulator. A thermionic gun with a barium oxide cathode was adapted for photocathode operation, and the performance of the gun was tested. Measurements showed the production of 200 pC of electrons with a normalized emittance of 5.5 mmmrad and a …
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Photoionization of Se Ions for the Determination of Elemental Abundances in Astrophysical Nebulae
… and Se5+. These measurements were performed at undulator beamline 10.0.1 of the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory using the merged-beams technique. All ions except Se5+ were measured from the energy region of the low-lying metastable state thresholds to at …
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Applications of Pulse-Magnetised Bulk Superconductors
… for a practical implementation of the technique. Undulators, used to generate high-energy X-rays in synchrotrons, make use of a strong spatially alternating magnetic field. This is another area of application in which bulk superconductors have demonstrated higher performance compared to permanent …
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Photoionization of the Cerium Isonuclear Sequence and Cerium Endohedral Fullerene
… cross-section measurements were performed at undulator beamline 10.0.1 of the Advanced Light Source (ALS) for nine parent cerium ions: Ce$^{+}$ -- Ce$^{9+}$. Double-to-single ionization cross-section ratios were measured for photoionization of the endohedral Ce$@$C$_{82}^{+}$ and empty …
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Photoionization and Photofragmentation of the Endohedral Xe@C60+ Molecular Ion
… is reported. Experiments were conducted at undulator beamline 10.0.1 of the Advanced Light Source (ALS) using the merged-beams technique. Prior to these measurements, macroscopic samples containing endohedral Xe@C60 were prepared using a setup developed at the ALS. Endohedral Xe@C60 yields …
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Measurements of FEL dynamics
… is positioned immediately following the undulator so that the gain medium—the relativistic electron beam—can be probed immediately following its interaction with the optical field in the laser cavity. The system permits real-time calculation and graphical display of key beam parameters as …
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XANES und MEXAFS an magnetischen Übergangsmetalloxiden : Entwicklung eines digitalen Lock-In-XMCD-Experiments mit Phasenschieber
… linear polarisierter Röntgenstrahlung an Wiggler/Undulator Strahlplätzen und zukünftigen XFELs (X-ray Free Electron Laser) durchführbar.
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Ankunftszeitbestimmung ultrakurzer XUV Pulse von FLASH durch Kreuzkorrelation mit ultrakurzen NIR Pulsen
… with electro-optical sampling in front of the undulator, has been found.
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Electron Beam Diagnostic at the ELBE Free Electron Laser
… simultaneously at ELBE. The first one, with an undulator period of 27 mm, is going to operate in the wavelength range from 3 µm through 30 µm. The second one is in the design stage only but it will be built to work at longer wavelengths from 25 µm to 150 µm where the FEL has no competition from …
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Magnetic X-ray Reflectivity
… magnetic hard x-ray reflectivity, providing an undulator beamline where the high flux of linear polarized photons was converted into circular polarization via a diamond phase plate, delivering much higher flux and better circular polarization. The sample used to demonstrate the feasibility of …