TY  - JOUR
AU  - Schneidmiller, Evgeny Alexanrdovich
AU  - Bermudez Macias, Ivette J.
AU  - Beye, Martin
AU  - Braune, Markus
AU  - Czwalinna, Marie Kristin
AU  - Düsterer, Stefan
AU  - Faatz, Bart
AU  - Ivanov, Rosen
AU  - Jastrow, Ulf Fini
AU  - Kuhlmann, Marion
AU  - Rönsch-Schulenburg, Juliane
AU  - Schreiber, Siegfried
AU  - Sorokin, Andrey
AU  - Tiedtke, Kai
AU  - Yurkov, Mikhail
AU  - Zemella, Johann
TI  - Two-Color Operation of a Soft X-ray FEL with Alternation of Undulator Tunes
JO  - Applied Sciences
VL  - 13
IS  - 1
SN  - 2076-3417
CY  - Basel
PB  - MDPI
M1  - PUBDB-2023-03447
M1  - arXiv:2211.07426
M1  - DESY-22-180
SP  - 67 
PY  - 2023
AB  - FLASH is the first soft X-ray FEL user facility, routinely providing brilliant photon beams for users since 2005. The second undulator branch of this facility, FLASH2, is gap-tunable, which allows for testing and using advanced lasing concepts. In particular, we developed a two-color operation mode based on the alternatingly tuned undulator segments (every other segment is tuned to the second wavelength). This scheme is advantageous in comparison with a subsequent generation of two colors in two consecutive sections of the undulator line. First, source positions of the two FEL beams are close to each other which makes it easier to focus them on a sample. Second, the amplification is more efficient in this configuration since the segments with respectively “wrong” wavelength still act as bunchers. We studied operation of this scheme in the regime of small and large separation of tunes (up to a factor of two). We developed new methods for online intensity measurements of the two colors simultaneously that require a combination of two detectors. We also demonstrated our capabilities to measure spectral and temporal properties of two pulses with different wavelengths.
KW  - free-electron lasers (autogen)
KW  - SASE (autogen)
KW  - two-color operation (autogen)
KW  - photon diagnostics (autogen)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000908842300001
DO  - DOI:10.3390/app13010067
UR  - https://bib-pubdb1.desy.de/record/585184
ER  -