Figure 6
(Top) THz transverse beam profiles at FLASH. (a) Dump magnet (the THz undulator is off), and (b) THz undulator tuned to 88 µm (3.4 THz), unfocused beam profiles measured in the THz hutch; beam position imaged 10 m from the virtual source. Note that the undulator profile is padded with zeros to fill in the same image size. (Bottom) The same beams focused. (c) Dump magnet beam (600 µm FWHM), and (d) THz undulator beam (350 µm FWHM). |