X-ray delivery

• 11.56 keV, 1-352 pulses @ 1.13 MHz, 2.6-3.1 mJ. Stable delivery.
• Intensity gradient with long train could not be reduced by BKR.

Optical laser delivery

• 840 nm, 50 fs, 564 kHz.
• Stable delivery.

Achievements/Observations

• Completed AGIPD programme.
• HIREX aligned for our trajectory and 11.56 keV photon energy. Thanks Naresh!
• Calibration of HIREX.

Issues

• Calibration of AGIPD data is slower than usual. Up to close to three hours calibration time observed for some runs and others taken around 2:30 still not calibrated as of now.

our pp laser experienced timing jumps by 18 ns today. this happened for the first time at ~7:30 in the morning without us noticing and a couple of more times during the morning. we realized it at 15:30 due to the fact that the signal on our pulse arrival monitor (X-ray/laser cross correlator downstream of the experiment) disappeared. we spent some time to investigate it, until we also see this jump in two different photodiodes different triggers (oscilloscope and digitizer) so it was clear that it is indeed the laser timing jumping. we also see the laser spectrum and intensity change for the trains that are offset in timing.

we called laser OCD at ~16:30. they have been trying to fix the problem by readjusting the instability zone multiple times and by adjusting the pockels cell, but this did not change the timing jumps. at 21:30 they concluded that there was nothing more they could do tonight and a meeting should happen in the morning to discuss how one can proceed.

effectively, this means that we lost the entire late and night shifts today for the pump-probe beamtime and have some data of questionable quality from the early shift as well.

we needed SASE1 to be set to 0 pulses briefly to check alignment in our experiment.

The FXE control hutch was empty. we could not reach either Chris nor Mykola by phone. The XFEL_StatusPublic shows that the FXE shutter is closed (we can also see the exp hutch door open from outside the control hutch).

Neither PRC nor BKR had any information about the FXE status.

We discussed with PRC and concluded that they are likely not using the beam, so in agreement with PRC we went ahead and got BKR setting SASE1 to 0 pulses at ~10:20. After few seconds, we got BKR setting SASE1 back to 30 pulses.

edit: PRC got in contact with FXE. Turns out they were (are) working in their ILH. we have a contact procedure for the next occasions now.

X-ray delivery

• 11.56 keV, 1-352 pulses @ 1.13 MHz, 2.6-3.1 mJ.
• Average intensity slowly decaying through the night.
• Quite some intensity gradient through the train (~35%).

Optical laser delivery

• 840 nm, 50 fs, 564 kHz.
• Stable delivery.

Achievements/Observations

• Collected data with AGIPD in various scenarios to better understand the behaviour of the 1.2 modules.

Issues

• SoundPlayer alarms not playing. Only way to fix it was to start the server manually via CLI.

Dear all,

Due to a probable issue at the SA1 Transmissive imager, the "OUT" and "YAG" position indication signals seems to be not responsive.

After the FXE team noticed that MODE S was interlocked, the root cause has been narrowed down to this component. Later, further investigation with A. Koch & J. Gruenert (XPD) has confirmed this fact. Apparently to recabling works performed during yesterday's ZZ may have something to do with this issue.

Once that the complete retraction of all the screen has been jointly confirmed via DOOCS and Karabo, the affected interlock condition (see attached picture) has been disabled for the rest of the week to allow normal operation of SA1 (release of MODE S and MODE M).

Further investigation and the eventual issue resolution is expected to happen on Tuesday next week via ZZ-access.

With best regards,

Raul [PRC@CW19]

• proposal 5700 finished on 04.05. The experiment used 352 pulses at 4.5 MHz and 18 keV to X-ray heat pressurized samples in diamond anvil cells. Overall succesful on several samples.
• Issues:
  • the requested 20.5 keV photon energy had too low pulse intensities so we had to go down to 18 keV
  • pulse energies at 18 keV (300-400 uJ) were insufficient for some samples
  • the ramp in pulse envelope has not been delivered consistently throughtout the experiment (eventually we gave up due to the average low pulse energies)

X-ray delivery

- 9.3 keV, 3.1 mJ, 214 pulses/train at 1.1 MHz and 132 at 0.5 MHz

Optical later delivery
- For jet illumination

Achievements/Observations
- Aligned IRU_SLIT-3 again
- Collected PCS data in fixed MG: a lot of diffraction for 5458, only very few for 7559.
- Collected Lysozyme data in fixed MG and adaptive gain.

Issues
- IRU_SLIT-3 right blade was too close to the beam. Physically shifted it by a few mm towards the dark side and improvised lead aperture added between IRU_SLIT-3 and inlinemic.
- LitFrameFinder cannot recognize dark runs for fixed medium gain. One needs to check box Disable DAQ Filtering (on LitFrameFinder scene) or enable Global Passthrough Mode in LitFrameFinder properties, when takes darks for fixed MG.

X-ray delivery

• 9.3 keV, 3.3 mJ, 190 pulses/train

Optical later delivery

• For jet illumination

Achievements/Observations

• Aligned NKB mirrors, slits again
• Removed the AGIPD shield
• Moved slit3 and slit4 to a fresh position after damage

Issues

• Litframe finder blocked collecting dark images for AGIPD. The problem was solved after resetting the Litframe finder.
• Slit3 and slit4 were damaged

X-ray delivery

• 9.3 keV, 3.3 mJ, 190 pulses/train

Optical later delivery

• For jet illumination

Achievements/Observations

• Aligned NKB mirrors, slits
• Collected 8 adaptive gain and 22 fixed medium gain runs with lysozyme
• Collected Copper foil flatfield data and glass scattering with different attenuation and sample-to-detector distances

Issues

• XTD2 attenuator watchdog limited the number of pulses to ~190 with XTD2 CVD inserted

840 pulses not possible at SXP due to big brother settings for the EPS Power Limit rule. The minimum pulse energy was assumed to be 6 mJ while the actual pulse XGM reading is 550 uJ.
Solution: The minimum assuemd pulse energy had been lowered from 6 mJ to 2 mJ. This shall be reverted on Tuesday next week.

V0 valve for SA2 closed as the pump P22090I at HED branch enters in wrong state. This closed nearby vacuum valves for HED branch and consequently V0. Vacuum levels at the section remained in 10^-9 all time.

Thanks to VAC-OCD Denis Finze we removed this pump signal from interlock to allow operation in SA2 at MID branch. Further investigation will follow on Friday.

instrument alignment including NaFos, DES spectrometer, diamond detector, PUMA & test samples
seeding makes a good impression based on the DES spectrometer

End of User beamtime 5157

20.4.2024 / 22h51:
DOC informed PRC that the SASE2 topic broker had to be restarted.
The EPS power limit was reset by PRC to the previous value of 40 W.

DOC and DRC are working on the restart. HED is in hardware setup configuration change (not currently taking beam, thus no harm to experiment),
will start taking beam with new users sunday 7am, but would need before this some test runs for the detectors. 

Currently the SA2 topic watchdogs (for ATT, CRL, imagers) cannot be restarted - they crash quickly after restarting.
DOC/DRC are investigating this issue. Until the watchdogs are successfully restarted, extra care must be taken when using ATT, CRL, imagers in SA2.

Update 21.4.2024 / 1h43 by DRC:
In a similar fashion to the incident of last 5.04, the Broker process for the SA2 and LA2 topic has restarted.
This was noticed by the DOC crew and by the HED crew in parallel.
With the help of the CTRL OCD (Micheal Smith) we restarted both topics. As a lesson learned from the last interruption, the POWER_LIMIT
middlelayer device has been set up by the PRC, so that when the DOOCS bridges will be restarted by the DESY-MCS personnel,
the maximum power will not be set to 0.
Please check in due time if all systems are working as intended.

Staff: JK, SB, JE, AS, RW, FK

**X-ray delivery:**
- 21 keV, ~500 uJ

**Optical Laser:**
- None

**Achievements / Observations:**
- Measured several Schimadzu runs

**Issues**:
- the beam intensity was fluctuating significantly during the day; 
- Changed the objective of Schimadzu for wider field then the controller stopped working which took over 1 h; before starting working again.
- One of the attenuators has features on the scene; Si 3200

The intra-bunchtrain feedback (IBFB) was not active until today afternoon.
Although not strictly required or requested for the current week experiments,
it was decided to turn on this feedback, which should generally be active to
stabilize and improve the arrival time of the photon pulses along pulse trains.

In order to avoid complications during long data acquisitions, the PRC checked back with all ongoing experiments,
identified a suitable time slot, and the IBFB was activated without issues at aound 16h45.

Measurements to check the impact of bunch compression on FXE mono transmission were successful. We could change the peak current between 4 and 12 kA and saw changes in bandwidth between 17 and 100 eV (at 14 keV). Results are under evaluation.

SA1 brought to safe state:

• CRLs moved out
• Mono moved out
• CVDs in XTD2 ATT inserted
• PBLM-based feedback was started and kept running to avoid beam drifting off of M3
• Hirex shutter closed
• The M1/M2 offset was decreased a bit as compared to saturday mornings' value (was very close to total reflection limit and to safely use 100 bunches, it was decreased to be on the safe side). Should not affect further measurements for XFELO on sunday.

Dear all,

we calibrated the mirror vertical motors to their geometrically neutral.

Please be aware that saved values for beamline settings may no longer be valid. This mainly applies to the vertical motor positions, but will have an impact on Tx and Ry values as well.

As starting point, use XRO Optics Setpoints 'C' - this setting was last used to bring beam to SPB