Figure 2
Averaged profiles of the exit beams measured with (a) BPM1 and (b) BPM2. The left (right) part of the profile in each panel shows the exit beam from the upper (lower) branch. Speckles as shown by the white arrows were caused by a Be window used for the upstream beamline optics and dust on the polyimide film of BIMs. (c, d) Typical single-shot beam profiles measured with BPM2. Differences between the profiles are due to the shot-to-shot profile and positional variations of the incident XFEL beams. The scale bars represent a length of 0.2 mm. |