| Paper | Title | Page |
|---|---|---|
| MOPB029 | Multi-bunch Operation Mode for Simultaneously Serving SASE and Seeding FEL Beamlines | 66 |
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| Modern free-electron laser (FEL) facilities are de-signed to simultaneously serve multiple undulator lines to provide x-ray pulses with high peak power and tunable wavelengths. To satisfy different scientific demands, it is preferred to make the separate undulator lines work under different FEL schemes, such as the self-amplified spontaneous emission (SASE) scheme and the echo-enabled harmonic generation (EEHG) scheme. However, different FEL schemes have differ-ent requirements on the beam longitudinal distribu-tion. Here, we propose to use multiple bunches to sim-ultaneously serve the undulator lines and put the bunches at different acceleration phase to change the bunch length with two compressor chicanes. The ac-celeration phase for each bunch is varied by adjusting the time delays of the photocathode drive laser pulses with the accelerator settings unchanged. The start-to-end simulation demonstrates that a fs bunch with high peak current can be produced to serve the SASE line while a bunch with hundred-of-fs length and uniform current distribution can be produced to serve the EEHG line. The FEL performances are simulated and discussed. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB029 | |
| About • | Received ※ 25 June 2023 — Revised ※ 10 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 07 September 2024 | |
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| TUPB033 | Heating Estimation of Undulator Vacuum Chamber at S3FEL | 151 |
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| Heating of the vacuum chambers are unavoidable when electron beams pass through the chamber channels at relativistic speeds. In the undulator vacuum chambers, such effects might lead to temperature increase of the magnets and eventually cause degradations in the FEL lasing process. Thus, in this paper, the heating of the undulator vacuum chambers at S3FEL due to wake field effects and spontaneous synchrotron radiation are estimated using an analytical approach. For the wake field effects, the contribution from finite conductivity of the vacuum chamber material and from the inner surface roughness are considered. A electron beam profile from a start-to-end simulation is used to calculate the total wake field and the induced heat. For the synchrotron radiation, a simple analytical expression is used. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB033 | |
| About • | Received ※ 05 July 2023 — Revised ※ 09 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 26 September 2024 | |
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| MOPB026 | Physical Design for EEHG Beamlines at S3FEL | 55 |
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Funding: Work supported by the National Key R&D Program of China (Grant No.2018YFE0203000) and the National Natural Science Foundation of China (Grant No.22288201). The proposed Shenzhen Superconducting Soft X-Ray Free-electron Laser (S3FEL) aims at generating FEL pulses from 1 nm to 30 nm. At phase-I, two undulator beamlines work at ehco-enable harmonic generation (EEHG) principle. The two undulators will cover the spectral ranges 2.3-15 nm (~83-539 eV) and 5-30 nm (~41-248 eV), respectively, when receiving electrons from 2.5 GeV superconducting linac. However, the generated FEL radiation is sensitive to various electron beam properties, e.g., its energy profile influenced by collective effects such as Coherent Synchroton Radiation (CSR), especially at high harmonics. To generate intense full coherent FEL radiation at ultra-short wavelength, a novel technique of EEHG cascaded harmonic lasing method is also considered. Physical design and FEL performance are described in this paper. |
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| DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB026 | |
| About • | Received ※ 10 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 18 July 2023 — Issued ※ 04 October 2024 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |