9.752 keV, self-seeding, 700-800 uJ.  Intensity is very stable, ponting is also much stable than usual. very good beam.

Beamtime #3326 - Axion search.

Successfully aligned two Ge crystals to Laue conditions (Rocking curve width ~0.002 deg) . Found Laue reflections after 2 crystals on Jungfrau detector.

We realized that the Xeryon rotation stages used for rotation of stage was wrongly calibrated (1 deg was not 1 deg), which caused some confusion. But we found a workaround solution. Still, we doubt about the repeatability and stability of the stage.

The biggest issue was that we lost the Laue reflection very quickly when we put a full intensity onto the crystal. The beam size is about 500 um FWHM. The Bragg angle at the heated sample fluctuate (does not go toward a single value).

We tested several different x-ray intensities to find the optimum flux where the Bragg condition stays. It seems, if we go to 0.1% transmission, the decay time is about 20 - 30min, which may be good enough for data.

We also discussed on swiching back to SASE. As the fluctuation of the Bragg angle seems to be  < 0.02 deg, which would be covered by  the SASE bandwidth. But, that means the photon energy goes to the second crystal fluctuate, then we lose the Laue reflection from the second crystal - probably going to SASE doesn't solve the  issue. This is the current situation.

We called DOC - Optics hutch attenuation stopped working - solved. Jungfrau2 data cannot be taken by DAQ - we decided not to solve this issue as JF2 is not necessary for this beamtime any more.