Paper | Title | Page |
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MOOA5 | Coherent Harmonic Generation at the DELTA Storage Ring | 5 |
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Funding: Supported by DFG, BMBF, and the Federal State NRW First commissioning results from a new Coherent Harmonic Generation (CHG) source, recently installed at the DELTA storage ring, are presented. DELTA, a university-operated synchrotron light source in Dortmund, has successfully operated an optical klystron as storage-ring FEL. After installing a Ti:sapphire laser system and new undulator power supplies earlier this year, the optical klystron can be seeded using ultrashort pulses at 800 nm wavelength and harmonics thereof during standard operation of the storage ring at 1.5 GeV. The energy modulation induced within a short slice of an electron bunch is converted to a density modulation and the micro-bunched electrons emit ultrashort pulses coherently at harmonics of the initial wavelength. Several meters downstream of the optical klystron, path length differences of the energy-modulated electrons cause a dip in the charge distribution, giving rise to coherent ultrashort THz pulses which are extracted using a dedicated beamline. |
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Slides MOOA5 [2.605 MB] | |
TUPA14 | Conceptual Layout of a New Short-Pulse Radiation Source at DELTA Based on Echo-Enabled Harmonic Generation | 219 |
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As an upgrade of the present coherent harmonic generation (CHG) source at the DELTA storage ring, the installation of an additional undulator to implement and study the echo-enabled harmonic generation (EEHG) scheme [1] is planned. Compared to the CHG scheme, EEHG allows to produce radiation of shorter wavelengths, thus reaching more relevant absorption edges. In order to avoid dispersive distortions, all undulators should be placed along a straight line. This requires to increase the length of the present straight section by rearranging several magnets and vacuum components as well as a significant modification of the storage ring optics.
[1] G. Stupakov, PRL 102, 074801 (2009) |
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TUPB10 | Echo Seeding Experiment at FLASH | 279 |
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Using the two perpendicularly oriented undulators and chicanes developed for an optical replica synthesizer (ORS) experiment together with the sFLASH 800 nm seed laser, radiator undulators and diagnostics, an echo seeding experiment will be conducted at FLASH in January 2012. For this experiment, the 800 nm laser pulse will be transported with a new, 12 meter long, in-vacuum laser transport line. On an in-vacuum optical breadboard, the 800 nm pulse will then be tripled in beta-BBO nonlinear crystals. The laser pulse will then be split longitudinally using a birefringent alpha BBO crystal into two pulses with orthogonal polarization states corresponding to the orthogonal orientations of the ORS undulators. These pulses will be focused to a 400 μm waist between the undulators with a Galileo telescope and steered with 4 motorized mirrors onto the electron beam axis in the ORS undulator section. The hardware layout and simulations of the echo seeding parameters will be described. | ||