This general purpose beamline delivers non-monochromatic FEL photons to user-provided endstations, either focused to ~20 µm or unfocussed (beamsize then ~7 mm). No permanent endstation is forseen. Additionally, optical laser radiation from the FLASH1 pump-probe laser can be provided for pump-probe experiments.

BL3 is the only beamline which allows to combine XUV pulses with THz pulses from the THz beamline for pump-probe experiments. 

As every user group has to provide its own endstation, this beamline is not restricted to a certain experimental technique. Indeed, the experiments already performed at BL3 range from photoelectron spectroscopy over scattering experiments to imaging of biological samples.