| Paper | Title | Page |
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| MOPCH018 | Macro-Pulse Generation in a Storage-Ring Free-Electron Laser: A Single-Particle Plus FEL Numerical Approach | 89 |
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| In a storage-ring free-electron laser (FEL), the onset and growth of intra-cavity power at the fundamental resonant wavelength is naturally accompanied by coherent emission at higher harmonics. Contrary to what happens in single-pass linac-based devices, the electron beam is re-circulated in the storage ring and the microbunching becomes thermalized. As a consequence, a correct theoretical understanding of the process requires a proper modelling of the turn-by-turn evolution of the electron-beam phase space, both inside the undulators (where the FEL interaction takes place) and along the ring. To simulate this process we have coupled an ad hoc modified version of the 3D numerical code Ginger (which models the FEL interaction) together with a linear one-turn map (which propagates the electron beam along the ring). We present our results and draw a comparison with previous simplified approaches. We also present the first benchmarking of experiments carried out with the ELETTRA storage-ring FEL. | ||
| MOPCH020 | Design and Optimization of the FERMI @ Elettra FEL Layout | 0 |
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| The FERMI @ ELETTRA project at Sincotrone Trieste will be comprised of two FEL's, each based on the principle of seeded harmonic generation. The first undulator line, FEL-1, will operate in the 40-100 nm wavelength range and will rely upon one stage of harmonic up-conversion. The second undulator line, FEL-2, extends the output spectral domain to the 10-40 nm wavelength range and will use two harmonic stages operating as a cascade. We review the FEL studies that have led to the final design and present results of numerical simulations with GENESIS and GINGER codes including those examining the effects of undulator errors and shot-to-shot fluctuations in multiple input parameters. | ||
| MOPCH021 | FERMI @ Elettra: Conceptual Design for a Seeded Harmonic Cascade FEL for EUV and Soft X-rays | 0 |
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| We present a summary of the conceptual design for the FERMI FEL project funded for construction at the Sincrotrone Trieste, Italy. The project will be the first user facility based on seeded harmonic cascade FEL's, providing controlled, high peak-power pulses, and complementing the storage ring light source at Sincrotrone Trieste. The facility is to be driven by electron beam from a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac. Designed for an initial complement of two FEL's, providing tunable output over a range from ~100 nm to ~10 nm, FERMI will allow control of pulse duration from less than 100 fs to approximately1 ps, and with polarization control from APPLE undulator radiators. Seeded by tunable UV lasers, FEL-1 is a single-stage of harmonic generation to operate over ~100 nm to ~40 nm, and FEL-2 a two-stage cascade operating from ~40 nm to ~10 nm or shorter wavelength. Photon output is spatially and temporally coherent, with peak power in the 100’s MW to GW range. We have designed FEL-2 to minimize the output radiation spectral bandwidth. Major systems and overal facility layout are described, and key performance parameters summarized. | ||
| MOPCH022 | Time-resolved "Start-to-end" FEL Simulation Results for the FERMI @ Elettra Project | 0 |
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The FERMI FEL project* is the first user facility based on seeded harmonic cascade FEL's, providing controlled, high peak-power pulses, and complementing the storage ring light source at Sincrotrone Trieste. FERMI will initial comprise two FEL's, providing tunable output over a wavelength range from ~100- to 40-nm (FEL-1) and ~40-to-10-nm (FEL-2) with control of both polarization and temporal pulse duration. We present results concerning the predicted FEL output based the expected 6D electron beam phase space at the undulator entrance as determined from detailed "start-to-end" simulations**. Both the GENESIS and GINGER codes were applied to this study. We discuss the expected transverse and longitudinal coherence, and also the predicted sensitivity to both undulator errors and accelerator jitter.
*C. J. Bocchetta et al. “FERMI @ Elettra – Conceptual Design for a Seeded Harmonic Cascade FEL for EUV and Soft X-rays”, this conference. **S. DiMitri et al. “Start to End Simulations of FERMI@ELETTRA”, this conference. |