The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
| Title | Reverse Undulator Tapering for Polarization Control at XFELs | |||||
| Authors |
|
|||||
| Abstract | Baseline design of a typical X-ray FEL undulator assumes a planar configuration which results in a linear polarization of the FEL radiation. However, many experiments at X-ray FEL user facilities would profit from using a circularly polarized radiation. As a cheap upgrade one can consider an installation of a short helical afterburner, but then one should have an efficient method to suppress powerful linearly polarized background from the main undulator. We describe a method for such a suppression: an application of the reverse taper in the main undulator*. In a certain range of the taper strength, the density modulation (bunching) at saturation is practically the same as in the case of non-tapered undulator while the power of linearly polarized radiation is suppressed by orders of magnitude. Then strongly modulated electron beam radiates at full power in the afterburner. The scheme was successfully tested at LCLS** and is routinely used in user experiments. In this contribution we present the theoretical description of the method as well as the results of experiments with reverse taper at FLASH2. | |||||
| Footnotes & References | * E.A. Schneidmiller and M.V. Yurkov, Phys. Rev. ST-AB 16, 110702 (2013) ** H.-D. Nuhn et al., "Commissioning of the DELTA polarizing undulator at LCLS", Proc. of FEL2015 Conf., Daejeon, Korea |
|||||
| Paper | download MOPOW008.PDF [0.285 MB / 3 pages] | |||||
| Export | download ※ BibTeX ※ LaTeX ※ Text/Word ※ RIS ※ EndNote | |||||
| Conference | IPAC2016, Busan, Korea | |||||
| Series | International Particle Accelerator Conference (7th) | |||||
| Proceedings | Link to full IPAC2016 Proccedings | |||||
| Session | Poster Session | |||||
| Date | 09-May-16 16:00–18:00 | |||||
| Main Classification | 02 Photon Sources and Electron Accelerators | |||||
| Sub Classification | A06 Free Electron Lasers | |||||
| Keywords | undulator, FEL, resonance, radiation, bunching | |||||
| Publisher | JACoW, Geneva, Switzerland | |||||
| Editors | Christine Petit-Jean-Genaz (CERN, Geneva, Switzerland); Dong Eon Kim (PAL, Pohang, Republic of Korea); Kyung Sook Kim (PAL, Pohang, Republic of Korea); In Soo Ko (POSTECH, Pohang, Republic of Korea); Volker RW Schaa (GSI, Darmstadt, Germany) | |||||
| ISBN | 978-3-95450-147-2 | |||||
| Published | June 2016 | |||||
| Copyright |
|
