Two-color operation of a soft x-ray FEL with alternation of undulator tunes

E. A. Schneidmiller, I. J. Bermudez Macias, M. Beye +13

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-tunab…