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

Shift summary 2024-02-23 07:00 - 2024-02-24 10:00

We got self-seeding at 8.5 keV very quickly after changeover from 10.5 keV operation finished at 2024-02-23 07:00.
Pulse energy ~ 600 uJ. 

Progress is in general good. Most of planned tasks for the day are done.
We called BKR whether we can get a bit more energy/pulse this morning, but it appears difficult. Otherwise, having a bit more energy would be helpful to have enough signal-to-noise ratio for X-ray imaging. 

Achievements: 

• Insert nanofocus lens, pump IC1 sample chamber into vacuum
• Establish X-ray axis, measure source point and divergence
• Set up the CRL scheme overfilling CRL4b nanofocus (the settings used in Feb at 8.2 keV were CRL1 arm 3,5 and CRL2 arm 1)
• Bring the imaging systems to the X-ray axis
• Focus and calibrate the x-ray spectrometers
• Laser-xray timing verified on YAG
• DAMNIT setup 
• Nanofocus imaging optimization (Z-scans) with Cu 25um wire and Siemens star
  • Best focus was identified
• Sample alignment 

Shift summary for 2024-02-24 from 07:00 to 2024-02-25 at 14:00:

Self-seeding at 8.5 keV, with approximately 500 μJ per pulse. Following re-tuning around 10 am on the 25th, the energy per pulse increased to around 600 μJ.

The x-ray intensity and pointing stability have been excellent, resulting in a substantial amount of data being acquired by users just two days into the beamtime. Users have expressed satisfaction with the performance thus far.

There were a couple of brief beam downtimes, but they had minimal impact on beamline operations.

Achievements:

• Successful laser delay scan (0 - 1000 ps) of wire compression dynamics under ultra-intense laser interaction (>10^21 W.cm-2).
• Nanofocus Z scan imaging completed.
• Online analysis tools (DAMNIT) are functioning properly.
• Some minor issues with the automatic shot procedure using MDL were encountered but mostly resolved.
• Ongoing issues persist with the off-axis-parabola mirror X axis (motor movement not stopping), which will require follow-up after the beamtime.
• A minor issue was identified with laser timing jumps, possibly stemming from a trainID distribution issue with the ToD system. Increasing the sequence delay of the master timer from 10 to 30 appears to have mitigated this problem.

Shift summary for 2024-02-25 from 11:00 to 2024-02-25 at 14:00:

Self-seeding at 8.5 keV, with approximately 500 μJ per pulse. 

Overall, the performance of x-ray self-seeding remains good, and users are happy. Pointing stability is also exceptional. However, enhancing photon energy slightly (600 uJ as we had yesterday) would further improve the signal-to-noise ratio.

Key Achievements and Current Challenges:

1. Ongoing data accumulation.
2. Issue with the sample motor (stepper motor). The encoder ceases to update values although the motor is actually moving. While a temporary workaround has been implemented, a thorough investigation is needed post-beamtime. More details: [Link]

• 10 keV beam
• Detector: JUNGFRAU in the burst mode (16 memory cells)
• Achievements:
  • multiple sfx data sets (lysozyme) with 4 and 8 pulses (at 1.1MHz) per exposure taken

In-house/commissioning beam time summary night 5

X-ray delivery:
12.7 keV, up to 128 pulses at 0.5MHz, ~1.3 mJ, one very short beam down.

Optical laser delivery:
PP laser for illumination

Achievements/observations:
- AGIPD1.2 tests with different trigger delays, gain modes, signal levels ...
- inhouse proghram completed

Issues:
Some sample delivery issues

beam parametes: 8.5-9 kev, 1.2 mJ, 1-2 pulses

• HED trajectory established from XRO setpoint, shape and transmission optimized
• monochromator aligned
• 5 sets of CRLs including nano-focus aligned
• ZZ yesterday morning to fix cameras, connect motors..
• DAQ rolled back to legacy version, works fine
• instrument spectrometers aligned and calibrated
• We perform some longer scans with monochromated beam imaging on wires / Siemens star
• Work on shimadzu timing
• Debugging new JNGFR_DARK_CHAR middle layer with controls - done

*Achievements :
- Generally rather successful with very high quality beam parameters
- We had a nearly steady 800 uJ+ HXRSS flux during the user run and ~ 4mJ SASE during the setup at HED.
- Beampointing was rather stable throughout the HXRSS operation.
- Users took several shots (>2600 FEL and FEL+ReLAX shots) on target. The beamline setup was very quick prior to that and users were able to get preliminary data to prototype parameters already a day before formal handover to them and could straight go to harvest mode on Saturday morning.  
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* Issues :
- Users still found large Bremsstrahlung fluxes on their background, but this is rather on our side, in conjunction with the users.
- On the last day, we had issues with JF calibrations due to the high run numbers in the proposal. DOC promptly helped out.  
- Initially, we observed fluctuations in the FEL flux. BKR was very prompt to correct for this and user operation was not impacted seriously. Slow drifts in pulse energy were also observed, but again, could be compensated from time to time by them.
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• 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)

beam parameters: 2 colors at around 6.5 keV, 1 pulse

achievements:

user program continues with data acquisition at slightly varying photon energies (tens of eV both colors simultaneously) and at different delays between the colors

Issues:

• users have scheduled datasets to be measured overnight with larger delays up to 350 fs, however, the BKR was able to go only up to 100 fs delay despite having larger delays earlier in the experiment (even during nights)

- M3 TX moved to 0 in steps of 1 mm and beam on FXE Pop-In corrected with M3 RY (+) and M2 RY

- Started calibration with M3 Rz in steps of 0.5 (+) and corrected with M2 RY and RZ to find a position with a minimum of parasitic motion

- Iterations with M3 TY

- CRL 3 and 4 were inserted (using find target)

- The backlash correction was disabled

- Curve for M3 Rz position with Ry correction done. M2 RY/RZ corrections to move beam up and down to have it on the screen

- Curve for M3 Ty position with Ry correction done.

- Curve for M3 Rx position with Ry correction done

M3 vertical motors calibrated to 0

We plan to put the piezos of M2 off, in the (unprobable) case that this is the reason of the "jumps" in SASE3 trajectory.

Therefore, I measured the change on RY and RZ motors, to correct all the positions

Fig 1: initial position, Motors Ry=10.5425 and RZ=-14.7200  Piezo Ry =5 and Rz=5

Fig 2: Ry is compensated, Motors Ry=10.4990 and RZ=-14.72  Piezo Ry =0 and Rz=5

Fig 3: Rz is compensated, Motors Ry=10.4990 and RZ=-14.7574  Piezo Ry =0 and Rz=0

Differential values: RY needs to be adjusted by -0.0435 and Rz by -0.0374

goals achieved:
alignment of the beam in tunnel and hutches including refinement of the beam in the center of rotation 
check of cameras and optical components
initial check of the mirror chamber (successfully)

issues:
smarACT motors in the DES tricky - some are in error state and the filter wheel is moving and does not stop - positioned it and removed afterwards the cable - EEE intervention next week necessary
camera of Pop-in imager II45-2 in XTD6 went into error - DOC solved the issue

check of the optimized focussing options at 10 keV using only one arm in CRL2 - results still to be evaluated
successful check of the mirror chamber in the experiment hutch of MID - it was possible to reflect the direct beam down and use it under a shallow angle on the sample position

Stable seeding with 1mJ + 400mJ SASE
HIREX triggered interlock when all attenuators are removed 
successful test of nano focusing setup
successful test and alignment of x-ray microscopes
Alignment of split and delay line
Laser x-ray timing at sample position

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

alignment of the instrument including collimation and beam shaping
test of the tempus detector using standard samples with different rep rates, intensities & # of pulses
start commissioning of the PhotonArrivalMonitor (temporal & spatial overlap, white light spectrum)

continue with Tempus tests
continue with PAM commissioning (first results of the working device at MID)

comments:
changed to 10 keV in order to use only one focussing lens in CRL2 and generating a smaller focus

issues:
vacuum issues in the MPC (reason: open roughing valve)
FSSS (hall sensor broken - exchange of the entire device planned for tomorrow)