ID09 is an undulator beamline for time-resolved diffraction, scattering and x-ray emission experiments. Most experiments use laser/X-ray pump-probe to "snapshot" transient states of the sample at a given delay between the laser and X-ray pulses. By varying the delay, the transient structure (or electronic state) is thus "filmed" with 100 ps time resolution. In addition a stopped-flow apparatus is available for probing irreversible reactions with 10 ms resolution.

The beamline can provide pink X-ray pulses of very high intensity. In 4-bunch mode for example, the U17 undulator produces 5 x 10⁹ ph/pulse at 15 keV in a 4% bandwidth. The beam is focused to 45 um by a toroidal mirror. The pink beam can be monochromatised by a multi-layer monochromator with 2.0% bandwidth or by Si(111) or Ge(111) crystals between 8-24 keV. 

The beamline has two choppers. The white beam is first intercepted by a heatload chopper that reduces the transmitted power to 12.5% (90 us pulses at 986.3 Hz) to relieve downstream components from high heatload. These pulses are focused to 45 um by a toroidal mirror. 1.5 m upstream the focus, the beam is intercepted by the Julich Chopper that can isolate single X-ray pulses from the 4-bunch, 16-bunch and 7/8+1 filling modes at 986.3 Hz. The pulse length of of X-ray pulses at the ESRF is 80-160 ps (FWHM).

The beamline has two laser systems for reaction initiation.A sapphire laser with 1.2 ps pulses that can be tuned by a TOPAS OPA in the wavelength range 265-1500 nm. That laser runs at 986.3 Hz. In addition, a 5 ns laser is available for protein reactions on slower time scales or for dynamic compression experiments at 1064 nm where the pulse energy is 350 mJ/pulse. The wavelength range is 354-1500 nm.