Beamline FL23

The new FL23 pulse-length preserving double-grating monochromator beamline is an open-port variable micro-focus beamline covering the FEL wavelength range of 1.2 – 20 nm (including FEL harmonics). The double grating monochromator design of FL23 will provide a narrow spectral bandwidth of the FLASH2 photon pulses while preserving the ultrashort (FEL) pulse duration of less than 50 fs. A Kirkpatrick-Baez mirror system employing bendable mirrors focuses the monochromatized radiation down to approx. 5 x 5 um beam size at the target, independent of the monochromator slit. Due to a moveable exit arm, the monochromator can be used in double- or single-grating configuration. The latter allows higher throughput and is particularly interesting when using harmonics at short wavelengths.

Photon Beam Parameter (Baseline Configuration)


Photon energy

3.5 – 20 nm (down to 1.2 nm including harmonics)


1010 photons

Focus size

5 um x 5 um FWHM (variable)

Pulse duration

<100 fs FWHM

Resolving power

Resolving power > 2000


Single (high transmission) & double grating (pulse length preserving)


Günter Brenner
E-Mail: Günter Brenner
Phone: +49 (0)40 8998 4527, mobil +49408998-94527
Location: 28k / O2.020