Desy Laser group has fixed the issue about the laser Synchronization.

https://ttfinfo.desy.de/XFELelog/show.jsp?dir=/2024/41/07.10_M&pos=2024-10-07T14:51:12

Naresh

PRC

wk41

14:40hr

FXE and HED reported the laser synchronization issue. Informed to Machine RC. 

LbSync team couldn't fixed this issue remotely and on there way to Schenefeld to fix this issue.

Naresh 

PRC wk 41

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

01:49

Worked on the XPCS analysis packages
measured the TetraPack samples
continued with the levitation device

issues:

1. Jungfrau detector had an error - R. Shayduk restarted the device - it should be power cycled as described in the manual
2. The bunch number selctor does not work - the system didn't accepted 150 pulse but moved it back to 30 pulses - the machine switched off the user selection - should be followed up tomorrow

**X-ray delivery**

- 6 keV, ~2.8 mJ, continuous beam drift in vertical direction (both XTD2 & XTD9 XGMs)

**Optical laser delivery**
- ns laser for particle visualization

**Achievements/Observations**
- measured sample for almost whole day (about 100 runs x 5 minutes)
- Julabo chiller (AGIPD) is still on target (-32 degree)

**Issues**
- Continuous beam drift in the vertical direction: NKB focus was optimized almost every 2 hours
- Sudden intensity drop in SA1 when SA2 or SA3 changes the number of pulses.

X-ray beam is continuously drifting in the vertical direction (XTD9_XGM)
It affects our NKB focus and focused beam is also drifting continuously.

Beam is back. Current status:

SASE1 (SPB/SFX)

• 2.72 mJ, 352 bunches/train, 6 keV

SASE2 (MID)

• 880 uJ, 1 bunch/train, 8 keV

SASE3 (SQS)

• 4.56 mJ, 1 bunch/train, 400 eV (3.1nm)

A2 failure - downtime

The machine / RC informs (11h22) that there is an issue with the accelerator module A2 (first module in L1, right after the injector).
This causes a downtime of the accelerator of 1 hour (from 10h51 to 11h51), affecting all photon beamlines.

**X-ray delivery**

- 6 keV, ~2.8 mJ, stable delivery

**Optical laser delivery**
- ns laser for particle visualization

**Achievements/Observations**
- measured user sample for almost whole day (about 100 runs x 5 minutes)
- Julabo chiller (AGIPD) is still on target (-32 degree)

**Issues**
- MKB Ion pump error (issue fixed after resetting the device)
- NKB focus loosed. Focus reoptimized twice during the d2 shift

continued with the evaluation of the XPCS analysis packages
investigated the effect of alignment optimizations and forced misalignments on the contrast directly with the online XPCS tool
checked additional standard samples 

X-ray delivery

• 6 keV, ~3.0 mJ, stable delivery

Optical laser delivery

• ns laser for particle visualization

Achievements/Observations

• measured 1 sample roughly for 9 hours (hit rate went down in the afternoon)
• Julabo chiller (AGIPD) is still on target (-32 degree)

Issues

• NKB mirror drifted in vertical direction: it was optimized again at around 9pm
• extremely low hit rate even with sucrose (extremely few particles were observed in sidemic, 1 particle within a few seconds): maybe the aerodynamic lens should be cleaned

Bunch pattern SA1 / SA3

SQS requests to change the bunch pattern.
Currently SA1/SA3 run interleaved as 131313...
The first bunch in the train (for SA1, non-lasing in SA3) nevertheless is visible as a small pre-peak in the diode signal which SQS uses to check the timing.
Therefore SQS requests to change to 31313131....

It was checked with SA1 (SPB/SFX) and the accelerator experts that this should not cause any issues (AGIPD detector is running on dynamic trigger),
therefore it was agreed that SPB/SFX informs BKR when there is a good moment without data acquisition, and BKR will make this change after informing SQS.
This change will happen within the next hour (as of 15h20).

started initial alignment for the ptycho experiment 
Continued with XPCS measurement using the levitation device

issues: contribution of the 2nd harmonic of 8 keV at 16 keV visible on the Jungfrau detector - surpressing via mirror alignment not successful

X-ray delivery

• 6 keV, ~2.7 mJ, stable delivery

Optical laser delivery

• ns laser for particle visualization

Achievements/Observations

• NKB focus optimized
• ns laser aligned with particle beam
• particle injector position optimized
• measured 3 samples: roughly 2 hours per each sample
• one sample was measured with and without He gas
• Julabo chiller (AGIPD) is still on target (-32 degree)

Issues

• Beam drift in vertical direction: Rz has to be corrected during the measurement and moved by 0.2 mm in total in whole day (~18 hours)

Started the day with vacuum & detector issues
real start of the experiments only at about 6 p.m. 
measurement of a selection of samples (urea, ludox) using the levitation device

issues: vacuum (behind AGIPD), motor (bend2 of the DES was in error - used for the beamstop)

X-ray delivery

• 6 keV, ~2.8 mJ, stable delivery

Optical laser delivery

• ns laser for particle visualization

Achievements/Observations

• NKB focus optimized
• particle injection tested with gold nanoparticles
• ns laser roughly aligned with particle beam
• Julabo chiller (AGIPD) is still on target (-32 degree)

Issues

• XTD2_ATT Arm4 (600um thick CVD) is damaged (most probably last week)

600um thick CVD diamond (XTD2 attenuator) seems damaged

Attachment 1: 600um thick CVD diamond (Arm 4) OUT

Attachment 2: 600um thick CVD diamond (Arm 4) IN

Issue with SA3 Gas attenuator (SA3_XTD10_GATT) - SOLVED

Dear all,

after the reported issue by SQS colleagues regarding the impossibility to inject Argon, and after a first remote evaluation, we (VAC) have entered XTD10 to assess the status and verify the most probable working hypothesis: a manual valve in the supply line was closed (otherwise as expected). Joshua and Benoit confirmed it and the showstopper is now gone. The system is back to normal and standard operation can be resumed in any moment. 

A small remark: as Argon (or any other gas different from Nitrogen) is not the default operation mode, it is important that if needed, there should be an explicit request during the preparation of the operation tables with XO. This would help to avoid this kind of situations. Unfortunately sending a short notice e-mail just before the next run is clearly not recommended.

With best regards.

Issue with SA3 Gas attenuator (SA3_XTD10_GATT)

9h06: SQS informs PRC that the Argon line in GATT is not reacting on pressure change commands, no GATT operation, which is required to reduce pulse energies for alignment. VAC-OCD is informed.

ZZ access is required to check hardware in the tunnel XTD10.
SA1 / SPB is working on other problems in their hutch (water leaks) and don't take beam.
SA3 / SQS will work with the optical laser.
SA2 / MID will not be affected: there is also an issue in the hutch and MID currently doesn't take beam into the hutch, and would anyhow only very shortly be affected during the moment of decoupling the beamline branches.

9h45: BKR decouples North Branch (SA1/SA3) to enable ZZ accesss for the VAC colleagues.

ZZ access of VAC colleagues.

10h12: The problem is solved. A manual intervention in the tunnel was indeed necessary. VAC colleagues are leaving the tunnel.

• Beam down SASE1: 9h43 until 10h45 (1 hour no beam), tuning done at 11h45, then 1.7mJ at 6keV single bunch.
• Beam down SASE3: 9h43 until 10h56 (1.25 hours no beam). Before intervention 4.2mJ average with 200 bunches, afterwards 2.5mJ at 400 eV / 3nm single bunch.