We fine tuned geometry parameters for linear effects on X motion (parallel offset) for all three mirrors.

dTz was corrected for M2 and M3 to -6.5mm (same geometry)

dTz was corrected for M1 to +6mm

for M2 we were able to do a parabola scan Y motion to check for lrTz

lrTz was then corrected to -433mm

correction in the same direction for M3 did not yield better results

Final mirror positions at HED - see picture

Laser status:

After the laser issues listed in https://in.xfel.eu/elog/OPERATION-2024/99 the late shift was finally able to find a timing setting for the amplifier trigger that was beyond stable settings under usual conditions, but which allowed to continue taking data runs for the rest of the beamtime reliably. The users were already able to reveal indications of a pump-probe signal in their data.

The issue itself remains but didn't show up in form of unstabilities anymore. After the beamtime LAS took some effort to investigate and narrow down to either a faulty trigger going into the front-end amplifier or on the front-end amplifier itself. To the best of our knowledge this circumstance will need to involve EEE support or even a service from the manufacturer and cannot be solved solely by LAS. LAS ensured that the highest priority will be to deliver stable laser pulses for next week's beamtime as well.

FEL status:

we found the FEL poynting to be very stable troughout the last weeks beamtime (despite some short down-times), which allowed to reliably verify the spatial overlap.

X-ray delivery

• 11.56 keV, 1-197 pulses @ 564 kHz, 2.6 mJ.

Optical laser delivery

• No PP laser output after shift change.

Achievements/Observations

• Collected static SFX data.

Issues

• Unavailability of PP laser prevented collection of TR-SFX data, which was the main goal of the shift.

EPS issue for Transmissive imager SA1 (OTRC.2615.T9) w.r.t Operation eLog #96

The motor screen positions w.r.t. the EPS switches had been realigned (last Wednesday 8th May), tested today (14th May) and the EPS is again enabled for the different beam modes. All is back to normal.

X-ray delivery

• 11.56 keV, 1-197 pulses @ 564 kHz, 2.4-3.1 mJ.
• Beam down a bit over 1 hour due to accelerator interlock problem.

Optical laser delivery

• 840 nm, 50 fs, 50 pulses @ 141 kHz.
• Stable delivery.

Achievements/Observations

• PP laser timed.
• Completed TR-SFX dataset at 30 ps delay.

Issues

• Scantool stuck in ACQUIRING state. Recovered by restarting the device.
• HIREX data missing for most of the night. GOTTHARD II control and receiver devices found down in the morning. Server on which they are reunning appears to have crashed at 1:36. DOC informed in the morning.

Weekend summary:

Overall stable beam delivery with 300bunches @18keV and 750uJ

-issue with XGM on Saturday night/morning

-The intensity in SA2 over the train is dropping of when SA3 is changing some parameters. BKR can fix it within a couple of minutes

-The users found suitable working conditions to overcome the limitations from the 10bar He supply line.

X-ray delivery

• 11.56 keV, 1-352 pulses @ 1.13 MHz, 2.4-3.1 mJ. Stable delivery.
• Intensity gradient with long train now slightly less than 20%.

Optical laser delivery

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

Achievements/Observations

• Collected TR-SFX data.

Issues

• Challenges with sample delivery.

X-ray delivery

• 11.56 keV, 1-352 pulses @ 1.13 MHz, 2.4-3.1 mJ. Stable delivery.
• Intensity gradient with long train better than previous shifts (~20% drop).

Optical laser delivery

• 840 nm, 50 fs, 564 kHz.
• Stable delivery.
• Issue with Treacy compressor motion. Could be solved, but required intervention on site by LAS and EEE OCD.

Achievements/Observations

• Calibration of HIREX GOTTHARD II data working after intervention of DOC/DRC.
• Finished PP laser setup.
• PP laser timed.
• Collected SFX data sets using AGIPD in different gain modes.

Issues

• All AGIPD dark processing attempts failed with random missing modules showing up in the reports.
• We were not able to reach the DRC to discuss the above issue earlier during the shift on either 98089, 98088, or 01715330920. DOC informed at end of the shift.
• HIREX had been removed from the SASE1 DAQ, preventing the GOTTHARD II preview from running, and the DAQ was left into passive state after someone had used it during the day with the XTD9 Shimadzu camera.
• Problem with the Treacy compressor delayed the final PP laser preparation, which then had to be done during beam delivery.

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.