IPAC2018 - List of Authors (Decking, W.)

Paper	Title	Page
THPMF022	Study of Possible Beam Losses After Post-Linac Collimation at European XFEL	4092
	S. Liu, W. Decking DESY, Hamburg, Germany F. Wolff-Fabris XFEL. EU, Schenefeld, Germany
	The European XFEL has been operating with the undulator beam line SASE1 and SASE3 since April 2017 and February 2018, respectively. Despite of the fact that the post-linac collimation has collimated the beam halo to ~20 σ level, relative high radiation doses have been measured especially in the diagnostic undulator (DU) section. In order to find the sources of beam losses after post-linac collimation, BDSIM simulations have been performed. In this paper, we will first present the possible losses generated by the wire scanners upstream of the undulators during a scan. The simulation results will be compared with the measured doses along SASE1 and SASE3 undulators. Based on the simulation results, we will estimate the frequency for wire scanner opera-tions. Besides, the simulations with large extension of beam halo hitting the vacuum chamber aperture transition will also be presented. Finally, other possible radiation dose sources will be discussed. S. Liu et al., in Proc. of FEL 2017, Santa-Fe, USA, Aug. 2017, paper TUP003. ** F. Wolff-Fabris et al.,IPAC-2018 contribution.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF022
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Paper

Title

Page

Study of Possible Beam Losses After Post-Linac Collimation at European XFEL

4092

S. Liu, W. Decking
DESY, Hamburg, Germany
F. Wolff-Fabris
XFEL. EU, Schenefeld, Germany

The European XFEL has been operating with the undulator beam line SASE1 and SASE3 since April 2017 and February 2018, respectively. Despite of the fact that the post-linac collimation has collimated the beam halo to ~20 σ level*, relative high radiation doses have been measured especially in the diagnostic undulator (DU) section**. In order to find the sources of beam losses after post-linac collimation, BDSIM simulations have been performed. In this paper, we will first present the possible losses generated by the wire scanners upstream of the undulators during a scan. The simulation results will be compared with the measured doses along SASE1 and SASE3 undulators. Based on the simulation results, we will estimate the frequency for wire scanner opera-tions. Besides, the simulations with large extension of beam halo hitting the vacuum chamber aperture transition will also be presented. Finally, other possible radiation dose sources will be discussed.
* S. Liu et al., in Proc. of FEL 2017, Santa-Fe, USA, Aug. 2017, paper TUP003.
** F. Wolff-Fabris et al.,IPAC-2018 contribution.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF022

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)