FXE received the beam and did not change accelerator settings.

Beam alignment to FXE was re-established using the new values for the old M1/M2 offset.

Monochromator aligned to the SPB energy setpoint.

THz source aligned to Xrays and several reference positions for Xray pointing taken. Further steps require THz radiation, which is not available at this point.

Xrays realigned back to SPB XTD9 screen.

On Shift: TS, FT, CK, AR, PS

X-ray delivery
8.951 keV, 1.6 mJ up to 200 pulses at 0.5 MHz (intesity drops off at end of train)

Achievements/Observations
Beam trajectory and focusing re-established at 8.951 keV
Temporary beamstop verified position for sweeping - confirmed by eric
Beam sweeping in synchronisation with pulse trains observed!
slit window assembly remounted and beam is going through to back of hutch in perparation for optimisation next shft

- DAQ was crashed after taking darks of AGIPD. It was solved by DOC and OCD.

- Laser could not switched from optical to RF lock. Solved by OCD (using doocs).
- Energy scan was attempted, which was not successful. 
- Seeding optimization was ongoing. It will continue tomorrow morning. Still there is intensity loss during the energy scan.
- We might see second (maybe higher) photon energy component on the beam. (https://mylog.connect.xfel.eu/#narrow/stream/201-MID_6877_UrsStaub/topic/.E2.9C.94.20Troubleshooting/near/72056)
- The beam was focused with CRL 2 arm 4 and 5. A precise beam size measurement would be useful. 
- The timing of XFEL and PP laser has been found from a frosted-YAG on the X-ray eye. T0 = 1374.94.
- The air gap between the MPC and DES are closed. 
- The first user sample is mounted and delivered in the PUMA setup.
- The spatial overlap of XFEL and PP laser has been found at the sample position with YAG crystal.
- The substrate peak (th = 20.7, tth = 41.4) was found on the fluorescent screen. 
- The SDL diamond detector was aligned on the beam, and now move it out.

 
Tomorrow
- Continuing of optimization of seeding and improving the energy scan.
- Cool down the sample and search the film peak on AGIPD.

X-ray delivery

8.951 keV, 1.6 mJ

Achievements/Observations

Beam trajectory and focusing established for 8.951 keV
HIREX inserted for energy reference for calibration tomorrow
Temporary beamstop verified position for direct beam.
Mirror tank inserted to beam path

X-ray delivery

• 12.8 keV, 1-20 pulses at 47 kHz, 500-700 uJ.
• Pulse energy constantly decaying since ~3:00.

Achievements/Observations

• Continuous SFX data collection since 00:10.

Issues

• Apparent mechanical issue with one motor. To be investigated before the restart of beam delivery.
• Beam horizontal drift still present, but not as pronounced as earlier this week.

Finally, the drift velocity of the pointing reduced approx a factor of 2 as compared to yesterday, see attached. Possibly it will still converge...

X-ray delivery

• 12.8 keV, 1 pulse, ~0.7 mJ

Achievements/Observations

• Except for some downtime due to beam down, majority of the time was for data collection
• 6 windows of a chip collected, with variations in shots spacing (30 um and 60 um) and rotation

Issues

• Something is still causing beam drift constantly, even though we can correct it with the feedback.

We observe a continuous horizontal beam drift in SA1 after the M1 incident. It seems not to converge, so one can wonder where this will go....

Attached screenshot shows the M2 piezo actuator RY that keeps the beam at the same position on the M3 PBLM. These are about 130 m apart, The drift is 1V/12 hours. 0.01V corresponds to a beam motion by 35 um. So the drift velocity is 0.3 mm/hour. In the past days this had at least once lead to strong leakage around M2. But the two feedbacks in the FXE path are keeping the beam usable most of the time.

X-ray delivery

12.8 keV, ~0.8 mJ

Achievements/Observations

- Data collection with fixed target

Issues

- M1 and M2 position on SPB/SFX Setpoint J was far from optimal
- Beam position in X was drifting to minus direction all time 

What has happened:
During euler motion calibration of M1, we were driving the vertical motors by a few mm back and forth. At some point, the Rz motor went into error, as we attempted to go further in negative direction. Resetting the axis several times did not solve the problem. The vertical motors were then moved to 0 position. DOC was called and helped to overwrite some parameters that triggered the error.
When resuming the calibration routine, the beam suddenly got lost and the vacuum interlock triggered V0 to close. Vacuum in M1 recovered quickly, but on M2 popIn, only the direct beam could be seen. At this point, the conclusion was that one of the motor connections must have come loose, which caused the vacuum event and removed M1 from the beam.

It was then decided, that we break the interlock, vent the chamber and re-connect the motor if possible.

The situation we found was the following:
-Rz connection lead-screw to bellow was detached
-mirror sitting on the mirror holder
-significant InGa spillage on chamber bottom, window flanges opposite to the mirror AND a lot of drops on the mirror surface

Pictures are attached.

Intervention:
The lead-screw and nut were exchanged. There was significant wear on the bearing plate, connecting the lead-screw to the bellow.
When trying to install the new lead-screw with a spare bearing plate, it was found that apparently the thread on the bellow side was deformed as well, and the spare part did not fit to the thread. Since the old bearing plate was the only possible way to connect the lead-screw to the bellow, it was cleaned, lubricated and re-used. The position was manually adjusted around 0 position (66,7mm protrusion) and the motor connected.

Recommendations:
- since the damaged bearing plate was re-installed, it should be avoided to move Rz. The motor should be permanently interlocked and only operated with absolute care for initial alignment.
- the mirror surface is severely contaminated with InGa, it must be checked if a position with acceptable beam can be found (only to be done by XRO as this needs Rz to be moved)
- the affected bellow has to be exchanged to facilitate replacement of the damaged bearing plate. As this requires the mirror chamber to be opened, this only makes sense in connection with replacement of the mirror + cleaning of the chamber.

X-ray delivery

• 12.78 keV, ~1.3 mJ

Optical laser delivery

• 800 nm laser for jet visualization

Achievements/Observations

• Collected SFX data
• Calibration date for HIREX measured (at different X-ray energy)

X-ray delivery

-12.40 - 12.82 keV, ~1.3 mJ

Optical laser delivery

-800 nm laser for jet visualization
-525 nm ns laser for pumping

Achievements/Observations

-Focus IRD
-Collected SFX data

Issues

-SPB_EHC_VAC/DCTRL/GAUGE_FR_1_Value triggered interlock, we could not open gate valve : SPB_IRU_VAC/VALVE/VALVE_INLINE_3

X-ray delivery

-12.40 - 12.82 keV, XDT9 XGM ~0.85 mJ, 3 hours interruption by vacuum issue on XTD9

Optical laser delivery

-800 nm laser for jet visualization
-487 nm ns laser for pumping

Achievements/Observations

-Focus IRD
-Collected SFX data
 

Issues

-AGIPD chiller was down
-Issue with tunnel vacuum valves, at around 7 pm, ended shift early

X-ray delivery

-12.40 - 12.82 keV, XDT9 XGM ~0.81 mJ@ end of shift

Optical laser delivery

-800 nm laser for jet visualization
-487 nm ns laser for pumping

Achievements/Observations

-Focus IRD
-Collected 10 ns SFX data

Issues

-AGIPD chiller was down

Used 9.4 keV with 94 kHz wed and thu nights. Received approx. 0.9 mJ with large fluctuations in pulse energy, however acceptable for the tasks below.

Achievements:

• X-ray optics and goniometer aligned for next user experiment 5725
• Transmission through Mono #2 recovered and calibrated to match Mono #1
• Understood uneven beam profile of FXE PI originating from the thick XTD2 ATT CVDs. Without them, the beam looks nice.
• Observed that overbending M2 gives better beam profile than underbending under the present conditions

Issues encountered:

• Major issue: M3 RY piezo actuator not working any more. This means beam feedback cannot run and beam keeps drifting off on the instrument apertures. This cannot be compensated by M2 piezo due to the small aperture of M3. The issue was reported wednesday night to PRC, XRO and FXE group and is being worked on by XRO
• One limit switch was found swapped; fixed by FXE engineers
• Some motors moved in the opposite direction as compared to previous commissioning, even though parameters were saved and restored. Not understood, but was easy to work around.

X-ray delivery

12.40 - 12.82 keV, ~1.1 mJ

Optical laser delivery

ns laser for jet visualization
ns laser for pumping ready but not used

Achievements/Observations

• Focus IRD
• ns time and spatial overlap
• Collected lyzo data
• Collected dark rhodopsin data
• New opaque foil installed on cube X-ray exit side

Issues

• Roadrunner motor issues solved after manual intervention and computer restart

X-ray delivery

12.40 - 12.82 keV, ~1.1 mJ

Optical laser delivery

800 ns laser for jet visualization

Achievements/Observations

• 800 ns laser for jet visualization (aligned but not timed)
• Jungfrau timing done
• IRDa focus done
• IRDa fully aligned
• Sample delivery ready
• Powder data collected

Found the interference fringe at Suna microscope with Zyla cam from MID split-and-delay line. 
The fringe patterns were recorded as a function of delay controlled by the upper branch motor position. 
Obtained the interference fringe patterns with two pulses with different repetition rate of machine. 
BKR provided the two color HXRSS seperated by a few eV, and SDL was aligned accordingly. 
The fringe patterns were recorded as a function of delay with two X-ray photon energies.

Found spatial overlap at Suna microscope with Zyla cam.
The splitting ratio was obtained about 1:1. 
The spatial jittering from upper and lower branch were investigated.
The temporal overlap and fringe will be investigated further.