Figure 6
Interference pattern at maximum visibility of partially overlapping pump- and probe-beams on a fluorescent screen ∼80 cm after the focus in CAMP. The fringes appear at temporal overlap (zero time-delay) and disappear at a few femtoseconds time-delay, consistent with the coherence time of the FLASH FEL at 13.5 nm (see text). Note that in order to overlap both beams on the screen, focal overlap had to be abandoned during this measurement. |