2 color mode

Achievements

• Fluence scan
• delay scan to identify cross talk of two colors
• Optimized beam size

Problems

• Struggle to find the expected signal when scanning color 2 energy
  • Optimized conditions

Plan for the rest of the night

• Repeat energy scan with optimized conditions
• Maybe try at a different delay

Achievements

• Work on laser to improve the beam profile and reduce pointing. Apertured the beam upstream of focusing lens and changed to f=750 mm. Significant improvement.
• Characterized beam size, found positions of photodiode, antenna
• Check coarse timing with reference
• Aligned FEL beam to sample

Problems

• Problems with smaract stages
  • Fixed with the help of DOC (Loic) by power cycling controller after long debugging.
• Beam down just before attempting coarse timing.

We report on an issue regarding the bunch pattern: The bunch pattern read by SCS_RR_UTC/MDL/BUNCH_DECODER shows 48 pulses, but we instead use 50 pulses.

Currently, we have a separate RF window and our 1st pulse Id is 2604. We operate at 2.2 MHz, and as required, 50 pulses. See attachment 1.

This means that the last two pulse Ids are 2700 and 2702. However, these values exceed the number of pulses allowed, and the way the bunch pattern is read (SCS_RR_UTC/TSYS/TIMESERVER:outputBunchPattern,
and the middle layer SCS_RR_UTC/MDL/BUNCH_DECODER) cast the array to 2700 values, so that the number of pulses read is 48 instead of actual 50.

We confirm that we indeed have 50 pulses, as seen by the XGM and by photodiode traces showing 50 peaks.

Since our data analysis strongly relies on the bunchpattern table, this is a critical issue.

For now, the users agreed to use 48 pulses instead of 50 pulses to facilitate the data analysis, but this issue should be investigated.

DOC was called, ITDM is aware and helped finding the reason.

edit 20 Apr 2023, 16:26 : redmine ticket https://redmine.xfel.eu/issues/151949

Achievements

• Optimized THz EOS, managed to observe single shot EOS trace with good SNR
• Characterized chirp with different glass lengths
• Ran SiN spectral encoding in parallel

Issues

• No major issue

# Late shift summary 29.09.2023

Laurent, Phuong
## Achievements
- Continue tr-RIXS
- Laser fluence scan
- Check PPL 266 nm power
- Setup DAMNIT

## Problems:
- online analysis not displayed on gui1 server fixed by DOC

## Plan for the night:
- continue tr-RIXS
- monitor energy and position drifts

06:45

22 Mar 2023, 17:08 started the log, the aim for the shift is the alignment of the sample and source point measurement. In addition to that, we also plan to check the Greateyes camera.

22 Mar 2023, 17:53 continuing the sample alignment

22 Mar 2023, 17:54 SAMP_AY is the clockwise direction looking from the top. Positive is towards the smaller incident angles.

22 Mar 2023, 17:57 By moving negative in the coordinated move we brought the sample towards the sliding door when the direction is 90°.

0deg_-alignment-FS.png shows blocking the x-ray beam with the sample.

22 Mar 2023, 18:13 We moved the target paralell to the XFEL beam so that we can either see the direct beam or we block the beam with the target. The next step is to block half of the beam with the target.

direct-beam-0deg.png shows the beam passing by the sample.

22 Mar 2023, 18:39 New zero position is found as on the screenshot New_zero_position_2023-03-22_18-39-16.png 

22 Mar 2023, 19:31 A clear Specular reflection is seen (c.f. Specular_and_reflected_beam_2023-03-22_19-22-19). We now do the angle per px calibration.

22 Mar 2023, 19:35 Specular reflection moves by 41 px for 0.02 deg rotation of the Samp_AY stage. Hence, 20px/0.01deg = 0.00049deg/px

22 Mar 2023, 19:37 We move by 113p = 0.055 deg on Samp_Ay to see the direct beam w.r.t the original sample position. We now move Coordinated motion.

22 Mar 2023, 19:43 Sample aligned parallel to the FEL beam - screenhot attached

22 Mar 2023, 19:48 Sample aligned to an AOI of 0.5 degrees. Screenshot attached. Remember the 2theta shift in the beam angle when the sample stage is rotated by theta. (c,f, AoI_0p25deg_2023-03-22_19-48-29.png - note the angle in file name corresponds to SampAy). Aligned position of the sample is FS_nearbottom_aligned_0.5deg_22032023. This position should be close to the edge at the bottom part of the sample.

22 Mar 2023, 20:54 Direct and Specular beamstops were aligned roughly with ALAS with the IC1 open by CB. We noticed that the breadboard of the specular beamstop motor is not fixed. We now check if this position is fine with the FEL beam without IC1 being pumped. CRL4a shall be driven inside to align this better from the control room.\

22 Mar 2023, 21:52 Direct beam stop was aligned with FEL beam. Specular beamstop was aligned horizontally. Specular vertical axis is only roughly centered.

22 Mar 2023, 22:25 Adjusted c-slits since they were clipping the beam before. p-slits are aligned as well.

22 Mar 2023, 22:48 Now we try to see something on the Greateyes. We bring in Relax alignment laser. Removed filters in IC1, free position in spectrometer. Switched off sensor power. Please insert the filters again before any laser shots!

22 Mar 2023, 23:10 We see something, but not clear what it is. Att. #7

beam parameters: 18 keV, 1 pulse on demand, 400 uJ

achieved:

• VISAR calibrations
• timing between X-rays, VISAR laser and DIPOLE laser
• main shots with DIPOLE energies up to 35 J, 10 ns flat top -> shock wave compression experiments on user targets

night shift changed the phase plate to 250 um, re-aligned everything and continued with user programme succesfully

issues:

• cryostat for the 100J is icing and needs to be defrosted which takes about 1 hour. The frequency of this happening is increasing - Over the last 24 hours it happened 3 times
• slowness of controls - especially Karabo playground MDLs
• slowness of DAMNIT and extraction of data tiff files
• ADQ412 (HED_EXP_IC2/ADC/1) stops randomly acquisition on its own

X-ray beam delivery relatively stable, could make use of bit higher pulse energy. Mirror feedbacks work fine

X-ray parameters: 20 keV (20080 eV from HIREX), 352 pulses, cca 250 uJ

• changed setup to diamond anvil cell experiments with laser heating
• installation of AGIPD detector
• running user samples, mostly carbon materials to constrain the phase diagram of carbon at high pressures and temperatures.

experiment going overall well.

X-ray performance:

• train with increasing tendency  of X-ray pulse energies but we found a workaround. X-ray heating still working to some extend even on carbon
• mirror feedbacks on and working
• CRL3 focus to below 10 um

AGIPD detector OK

beam parameters: 20 keV, 300 uJ, 352 pulses

• continuation of user programe.
• Machine performance very good for trying the 20 keV the first time. Experiment also going well.

beam: 18 keV, 352 pulses, ~200 uJ per pulse

achievements:

• AGIPD timing scans, AGIPD darks.
• beam alignment, CRL3 focusing, prep for the user beamtime

beam conditions:

• beam is jittering in position and pulse energies are on the lower end. The pulse train in decreasing in intensity

18 keV, 150 uJ per pulse, 2.2 MHz

• continuing user program proposal 3285
• X-ray heating and laser heating samples in DACs
• using only the first 200 pulses of the train as the intensity after decreases fast, conversion of the samples is difficult due to low pulse energies

Beam 18 keV, 0.5 MHz, long trains up to ~280 pulses

• change setup to dynamic DAC
• prep for user beamtime: alignment of X-rays, focusing (~40 um), train-on-demand for long trains, transmission runs
• darks, XRD calibrations for AGIPD

Issues:

• AGIPD may need a timing scan
• trains decreasing in intensity rapidly

• concluded user experiment on dynamically compressed water
• long train operation worked relatively stable with no major interuptions in beam delivery

beam parameters: 7.7 keV seeded, 2.2 MHz, up to 20 pulses, 150 uJ/pulse

• user program, measuring IXS spectra of plasmons with high resolution using seeded beam and monochromators
• mono (re-)alignment to minimize the SASE pedestal of the seed. Need to search for good position of the beam on the crystals as with just a slight change in pointing, the transmission goes down and deteriorates the beam spot
• haveing troubles getting good transmission through the mono
• taking spectra with the monochromatized seeded beam on PMMA, SiO2 and Al to be compared with the non-monochromatized cold spectra with 20 bunches.
• second half of the train is often not lasing though transmission of the pulses through the warm mono seems ok

beam: 7.7 keV seeded, ~300 uJ/pulse, 2.2 MHz, 20 pulses

• user experiment finilized, IXS scans on Si, Al and Cu at different momentum transfer angles
• measurements of plasmons in cold material only
• pulse energy increased slightly, however it is mostly in the SASE pedestal which is insufficient to caramelize the electrons into a souffle

• the initial 600-700 uJ of pulse energy at the beginning of the user beamtime dropped down to 300-350 uJ over night from 14th to 15th. The operators did not seem to be able to bring the pulse energy above 500 uJ, which is where it was after the RC's intervention in the morning. Is it possible to bring up the energy in the morning?

Beam parameters: 18.8 keV, 350-600 uJ, 1 pulse

Experiment: Shock compression experiments using DiPOLE 70 J + XRD

- run through most of the users targets, largely succesful

- photon delivery very stable on Sunday until Monday morning

- the beam went down on Monday 6am for an hour but got an extra hour until 8am, which is appreciated

Issues:

- HED XGM stopped showig controlData.slowTrain from about 4:30 AM. There seems to be some problem with the fast data

Beam parameters: 18 keV, 1 pulse, 600 uJ

- user beamtime started Friday, the 27th and going smoothly until now and we are in data collection mode

- shock compression setup with XRD and DiPOLE

- machine performance very stable in pulse energies with little downtimes