TY  - CONF
AU  - Brinker, Frank
AU  - Casalbuoni, Sara
AU  - Freund, Wolfgang
TI  - Correcting the Magnetic Field Offsets Inside the Undulators of the EuXFEL Using the K-Monochromator
M1  - PUBDB-2021-05192
SP  - 3953-3955
PY  - 2021
AB  - Hard X-ray free-electron lasers (XFELs) generate intense coherent X-ray beams by passing electrons through undulators, i.e. very long periodic magnet structures, which extend over hundreds of meters. A crucial condition for the lasing process is the spatial overlap of the electrons with the electromagnetic field. Well-established electron beam-based procedures allow finding a straight trajectory for the electrons defined by the beam position monitors (BPM) between the undulators. A bending of the trajectory in between the BPMs cannot be seen by these methods. A general field offset inside the undulators has the effect that the synchrotron radiation is emitted at a different angle at the beginning and the end of the undulator which can result in a degradation of the FEL-gain especially for very short wavelengths. We report on how the spectral and spatial characteristics of the monochromatized radiation of a single undulator can be used to minimize the field offset in situ with the help of correction coils.
T2  - 12th International Particle Accelerator Conference
CY  - 24 May 2021 - 28 May 2021, Campinas (Brazil)
Y2  - 24 May 2021 - 28 May 2021
M2  - Campinas, Brazil
LB  - PUB:(DE-HGF)8
DO  - DOI:10.18429/JACoW-IPAC2021-THPAB080
UR  - https://bib-pubdb1.desy.de/record/472717
ER  -