X-ray delivery: stable and flat over 190 pulses per train. 1.1 MHz with 200 uJ short intervention needed to improve intensity after it dropped

Optical laser delivery: NA

Achievements/Observations:

• Beam optimization and characterization
  - Short pulses tuned and number of spikes reduced
• X-ray focus FWHM calculation found to have a bug in pixel size used
  - rest to 0.2 FWHM of focused beam now better than 1.5 microns
• Laser illumination installed to enable particle visualization to aid alignment and feedback
• Sample injection and data collection for several hours
  - Hits seen from Silver cubes
  - very low hit rate from copper
  - cubes, and spheres

Issues:

• DAQ - multiple crashes and restarts needed throughout the shift
• Proc pipeline - some runs fail to processwhile adjacent runs collected with same conditions (run repeater) process without errors
• Sample injection - copper samples continue to be difficult to inject
  - very low hit rates (few hits seen per run)
  - clogging issues
• Focus drift - focus was tuned at around 3 pm, by 9 when we could check again focus was >3 microns FWHM
• Beam intensity reduced during the shift and BKR needed to tune it back
  - returned intensity to 200 uJ - they asked if we wanted to continue but did not as this could have resulted in more SASE spikes

X-ray delivery:

stable and flat over 190 pulses per train. 1.1 MHz with ~200 uJ

Optical laser delivery:

NA

Achievements/Observations:

Beam optimization and characterization
Sample injection and data collection for ~10 hours

reasonable hit rates observed but highly fluctuating, making alignment optimisation slow

Issues:
DAQ - restarts needed throughout the shift
Sample injection - copper samples dont give high hit rate and increaseing sample concentration led to clogging
Focus drift - focus was tuned at around 3:30 pm ( from 4 um back to 1.5 um)
-again at 19:30 when we checked again focus was >2microns FWHM returned to 1.5

X-ray delivery

• 9.10 keV; 190 pulses per train @1.1 MHz with roughly 170-200 uJ; stable delivery

Optical laser delivery

• ns laser for particles visualization

Achievements/Observations

• Sample injection and data collection for ~11 hours
• collected data on copper cubes with better hit rates than previous shifts; ~15%

Issues

• We had laser interlock issues, the magnet in door went to error state and this was fixed by Klaus Witt call around 22:15.
• data migration issues; it was very slow and DOC did not figure out the cause for this.

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, ~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

12.8 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 

X-ray delivery

    6 keV, ~2.8 mJ, continuous beam drift in both direction

Optical laser delivery

    ns laser for particle visualization

Achievements/Observations

    DAta collection for CDI
    Julabo chiller (AGIPD) is still on target (-32 degree)

Issues

    Continuous beam drift in the both direction: NKB focus was optimized almost every 2 hours

X-ray delivery

19 keV, ~550 uJ, 1 - 128 pulses, stable delivery

Optical laser

N/A

Achievements/Observations

Sample test with both setup
Siemens star resolution measurement 

Issues

No major issue

X-ray delivery

19 keV, ~450 uJ, 1 - 128 pulses, stable delivery

Optical laser

N/A

Achievements/Observations

Lots of data collection

Issues

No major issue today

We asked the machine for two color mode in the morning. Tuning gave good results at first (1.6mJ second color, 100uJ first color), but as soon as any of the colors was switched off and on again the pulse energy dropped (~600uJ) and BKR had to retune to even get a fraction of the pulse energy back back. The same happened when changing the delay

At 21:29:20 today, the number of bunches in SASE1 was increased from 1 to 352 without intervention of the SPB/SFX shift crew. 30 seconds later, the number of bunches was reduced to 1, again without intervention from the SPB/SFX shift crew (see attachments 1 and 2).

We were in the middle of a measurement at that time and the sudden increase from 10 mW to 3.5 W average power resulted in the destruction of the sample we were using.

AGIPD and JUNGFRAU are safe and were not at risk at the time of the incident, but this is merely by luck.

The origin of the change in number of bunches is unclear to us and needs to be investigated. It goes without saying that this is extremely dangerous for equipment and the damages could have been even worse.

X-ray delivery

• 1-352 pulses at 10 keV, 1200 - 400 uJ.
• Significant pulse energy slope within the train. Action on the kickers was eventually performed leading to some reduction of the slope, though remaining still far from ideal. Decision to take the action took a very long time (2.5 hours).
• Several beam delivery interruptions through the afternoon due to trips of A16 before is was taken off beam.
• At 21:29:20, the number of bunches in SASE1 was changed from 1 to 352 without intervention of the SPB/SFX shift crew resulting in the destruction of a sample (see elog:7).

Optical laser delivery

• 800 nm, 50 fs, 1-113 pulses at 564 kHz.
• Brief intensity and spectral fluctuations as already observed in the past with non-optimal AMPHOS regulation. Detail will be communicated to LAS.

Achievements/Observations

• Measured flat fields for AGIPD for all remaining configurations.
• Confirmed timing of JUNGFRAU.
• Established pump-probe timing at IRDa.

Issues

• Several issues with AGIPD controls: timeout when trying to stop sending data, two hemispheres in different states, etc. Experts informed.
• Destruction of the sample following number of pulses incident in the evening caused a considerable loss of time to replace the sample and resume operation.
• XTD2 500 um Si is damaged (leftover from last run).

X-ray delivery

• 1-64 pulses at 10 keV, ~1.1 mJ.
• Overall stable delivery.

Optical laser delivery

• NA

Achievements/Observations

• Measured flat fields for JUNGFRAU for all configurations. Detector program completed.

Issues

• Mishap of lit frame finder with custom bunch patter.
• Apparent issue to process JUNGFRAU darks caused by lack of disk space. Solved by DOC/CAL.
• Ghost run in myMdC upsetting the run controller. Solved by DOC and cause under further investigation.

Like after the previous winter maintenance period, the shutter of FXE appears as opened in DOOCS panels even though it is closed (https://in.xfel.eu/elog/OPERATION-2023/58).

X-ray delivery

• 1 to ~332 pulses at 6 keV, 4.5 mJ
• Stable delivery
• Number of pulses limited by the Photon Beam Power local limit that is set to 16 W. Is this intentional? All other limits are set to 40 W

Achievements/Observations

• Aligned NKB trajectory
• Achieved NKB focus
• Reduced background scattering on AGIPD
• Started data collection

Issues

• Identified a couple of problems with the new DAQ that we were testing. Controls group informed and investigating

The status of the XTD2 attenuators has been checked during the experiment last week and many were found to cause disturbances in the wavefront ranging from mild to severe.

Attachment 1: No attenuator
Attachment 2: 75 um CVD - Fringes visible in beam
Attachment 3: 150 um CVD - Strong fringes in beam
Attachment 4: 300 um CVD - Looks more or less ok
Attachment 5: 600 um CVD - Weak distortion in the beam profile
Attachment 6: 1200 um CVD - Ok
Attachment 7: 2400 um CVD - Ok
Attachment 8: 500 um Si - Not ok

X-ray delivery

• 10 keV, up to 160 pulses at 1.1MHz, 1.8 mJ

Optical laser delivery

• NA

Achievements/Observations

• Instrument aligned up to IRDa at 10 keV.
• Focus optimised.
• JUNGFRAU timed.

Issues

• We could only start using the beam at 1 am.
• More mirror movement needed to get the beam down the instrument than expected.
• Several AGIPD power cycling needed due to issues with MFPGA2

X-ray delivery

• 10 keV, up to 128 pulses with custom bunch pattern, 1.6-2.0 mJ

Optical laser delivery

• NA

Achievements/Observations

• Collected first SFX data, but background on JUNGFRAU is rather high and needs further optimisation.

Issues

• AGIPD having frequent problems with both MFPGAs (once even both at the same time). Frequent restarts were needed.
• Horizontal drift of the beam pointing.

The number of bunches during the last night shift kept being changed down to 24 by the device SA1_XTD2_WATCHDOG/MDL/ATT1_MONITOR020 acting on SA1_XTD2_BUNCHPATTERN/MDL/CONFIGURATOR. This was not the case during the previous shifts, even though the pulse energy was comparable. Looking at the history of SA1_XTD2_WATCHDOG/MDL/ATT1_MONITOR020, it looks like this device was started at 16:26:25 on Friday, 1st March.

We checked the XTD2 attenuators following the intervention from XRO (compar ewith elog:37, before the intervention).

The wavefront shows similar distortions with the 75 and 150 um as earlier, which is not too surprising since the cracks are vertical.

Attachments 1-5: Beam on SPB_XTD9_SCR with XTD2 attenuator CVDs

Attachments 6-7: Beam on FEL imager with XTD2 75 and 150 um CVDs