| Paper | Title | Other Keywords | Page |
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| TUP003 | Design of a Magnetic Bunch Compressor for the THz SASE FEL Proof-of-Principle Experiment at PITZ | FEL, radiation, experiment, undulator | 45 |
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| For pump-probe experiments at the European XFEL, a THz source is required to produce intense THz pulses at the same repetition rate as the X-ray pulses from XFEL. Therefore, an accelerator-based THz source with identical electron source as European XFEL was suggested and proof-of-principle experiments utilizing an LCLS I undulator will be performed at the Photo Injector Test Facility at DESY in Zeuthen (PITZ). The main idea is to use a 4nC beam for maximum SASE radiation but to allow different radiation regimes a magnetic bunch compressor can be used. This helps e.g. to reduce the saturation length inside the undulator and also to study super-radiant THz radiation. In this paper a design of a chicane type magnetic bunch compressor using HERA corrector magnets is presented. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUP003 | ||
| About • | paper received ※ 20 August 2019 paper accepted ※ 27 August 2019 issue date ※ 05 November 2019 | ||
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| TUP006 | The FHI FEL Upgrade Design | FEL, undulator, cavity, kicker | 52 |
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| Since coming on-line in November 2013, the Fritz-Haber-Institut (FHI) der Max-Planck-Gesellschaft (MPG) Free-Electron Laser (FEL) has provided intense, tunable infrared radiation to FHI user groups. It has enabled experiments in diverse fields ranging from bio-molecular spectroscopy to studies of clusters and nanoparticles, nonlinear solid-state spectroscopy, and surface science, resulting in 50 peer-reviewed publications so far. A significant upgrade of the FHI FEL is now being prepared. A second short Rayleigh range undulator FEL beamline is being added that will permit lasing from < 5 microns to > 160 microns. Additionally, a 500 MHz kicker cavity will permit simultaneous two-color operation of the FEL from both FEL beamlines over an optical range of 5 to 50 microns by deflecting alternate 1 GHz pulses into each of the two undulators. We will describe the upgraded FHI FEL physics and engineering design and present the plans for two-color FEL operations in November 2020. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUP006 | ||
| About • | paper received ※ 20 August 2019 paper accepted ※ 27 August 2019 issue date ※ 05 November 2019 | ||
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| THP033 | XFEL Isochronous Chicanes: Feasibility Study | quadrupole, FEL, electron, undulator | 658 |
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FEL schemes such as High-Brightness SASE [1] and Mode-Locking [2] require electron beam delays inserted between undulator sections. These schemes have been shown in simulations to perform most effectively when the electron beam delays are very close to isochronous, i.e. the first order longitudinal dispersion is very small. To minimise the disruption to the FEL process in the inter-undulator gaps, these delays must also be as compact as possible. In this paper we study the maximum longitudinal space that a delay chicane could occupy in an XFEL operating at 6 GeV before the peak power drops below a defined threshold, and we present a limit for the maximum longitudinal dispersion of the delay chicanes. We then present the optical designs of two chicanes that satisfy the requirements of length and isochronicity and show how these designs could be realised practically using small-aperture high-field quadrupoles.
[1] PRL 110, 134802 (2013). [2] PRL 100, 203901 (2008). |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-THP033 | ||
| About • | paper received ※ 16 August 2019 paper accepted ※ 09 September 2019 issue date ※ 05 November 2019 | ||
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| THP036 | Microbunch Rotation for Hard X-Ray Beam Multiplexing | quadrupole, focusing, FEL, undulator | 665 |
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Funding: This work was supported by the Department of Energy, Laboratory Directed Research and Development program at SLAC National Accelerator Laboratory, under contract DE-AC02-76SF00515. Electron bunches in an undulator develop periodic density modulations, or microbunches, which enable the exponential gain of X-ray power in a SASE FEL. Many FEL applications could benefit from the ability to preserve microbunching through a dipole kick. For example, X-ray beam multiplexing can be achieved if electron bunches are kicked into separate beamlines and allowed to lase in a final undulator. The microbunches developed in upstream undulators, if properly rotated, will lase off axis, producing radiation at an angle offset from the initial beam axis. Microbunch rotation with soft X-rays was previously published and demonstrated experimentally [1], multiplexing LCLS into three X-ray beams. Additional 2018 data demonstrated multiplexing of hard X-rays. Here we describe efforts to reproduce these hard X-ray experiments using an analytical model and Genesis simulations. Our goal is to apply microbunch rotation to out-coupling from a cavity-based XFEL, (RAFEL/XFELO) [2]. [1] J. P. MacArthur et al., Physical Review X 8, 041036 (2018). [2] G. Marcus et al. Poster TUD04 presented at FEL2019 (2019). |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-THP036 | ||
| About • | paper received ※ 24 August 2019 paper accepted ※ 26 August 2019 issue date ※ 05 November 2019 | ||
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