• We found that the x-ray pulse energy dropped a lot when we changed the undulator from 5.5 keV to 5.45 keV. We called BKR to optimise it (attachment 1)
  => There is a problem with the phase shifter of the undulator. It stacks sometime. If the x-ray intensity drops, we need to ask BKR to optimise it.
  => We were suggested not to change the undulator value by 100 eV. 5 - 10 eV step should be fine.

On the other hand, we had a user experiment 3435 Feb 2023, and we could perform photon energy scan from 5.7 keV to 6.1 keV without problem. (attachment 2)