Achivments:

-Measure delay scans at two PPL fluencies on smaller grain size.

-Moved DSSC back to 1.45 m sample - detector distance

Problems

-No major problems

achievements

• finished recording dataset at 20degree
• changed for sample with smaller grains at normal incidence and moved DSSC to 1.2m
• OL induced some change of the sample but the scattering ring remains and then stabilize
• started collecting data

problems

• issue with jupyter notebook slow processing. Asked DOC for 10 additional reserved nodes. Also found issue that 100's of Mb or error messages are saved in the jupyter notebook and found a solution to supress them https://in.xfel.eu/elog/3360+Duerr/92

X-ray delivery

• 12.4 keV 200 pulses / train, relatively stable intensity ~1.2 mJ / pulse

Optical laser delivery

• 420 nm PP laser
• ns laser for jet imaging

Achievements/Observations

• NKB focus checked and defocused to have about 3um(H) x 6um(V) beam
• Collected a few hours data with PP laser on both jet and nozzle excitations (AGIPD in adaptive gain mode)

Issues

• IRU Chamber LED was ON until 2:51am 
• Nozzle damage found after ~1 hour measurement 
• Hit rate seems too low still (less than 1%)
• Nozzle exploded close to the end of the shift 

achievements:

- measured delay scans at sample tilted by 20 degree

problems:

- we saw a drop in pulse energy around 00:30 in XGM at SCS, we verified that it was not because of the FEL not going through the HSLITS, in the end after calling BKR it was realized that there was indeed a problem with BC2, after fixing this, beam pointing was recovered and pulse energy as well

- beam pointing instabilities during tuning for SA1 around 6:30

achievements:

- measured delay scans at sample tilted by 20 degree

problems:

- we saw a drop in pulse energy around 00:30 in XGM at SCS, we verified that it was not because of the FEL not going through the HSLITS, in the end after calling BKR it was realized that there was indeed a problem with BC2, after fixing this, beam pointing was recovered and pulse energy as well

- beam pointing instabilities during tuning for SA1 around 6:30

- We get stable x-ray delivery with 130µJ.

- We could move the detector succesfully in and out of the LFoV configuration!

- We added a hole in in the black Kapton foil and increased the holes in the Kapton shielding of the jet. These were not positioned well, due to a misalignment of the ALAS. After this intervention we did not observe any scattering rings on the detector.

- We aligned the liquid jet and get a nice diffraction rings from water. 

Achivments:

-Measure time scans with magnetic field in opposite directions

Problems

-At some point data analysis was imposible. No reseurses could be dedicated for the analysis. We switch both AMORE and offline analysis to nodes, dedicated for the proposal.

-We found very slow drift of xray intensity at XGM. It was becasue x-ray pointing was slightly changed. We restore the pointing with M2 pitch motor

MID reports an observation that is particular to the operation at the currently high photon energy of 23 keV

MID inserted the XTD6-MID-preabsorber and assumed that it completely stops the beam.
They acquired AGIPD detector images as dark frames but were surprised to still find some weak background signal (not dark).
The explanation by PRC and XRO is that the purpose of the pre-absorber is to protect the shutters against potential
damage and not to entirely stop the beam like a radiation protection shutter itself.
The pre-absorbers contain diamond and B4C but no tungsten. The calculated transmission of the pre-absorber at 25 keV is 4%.
3rd harmonic of the FEL (here at 69 keV) is on the order of 1%, and MID uses the mirror coating
stripes for high photon energies, thus transmitting well these high photon energies.

As another result, the apparent beam size observed on the downstream imagers can be more complex to understand:
MID actually also reports that the beam size appeared larger in the afternoon than in the morning,
depending on the insertion status of the pre-absorber and the lenses.
The scintillation efficiency of the YAG screens is known to be high also for hard x-rays beyond 30 keV.
Additionally, the CRLs focus the various harmonics differently. When CRL1 is set to focus the beam,
it will likely defocus higher harmonics yielding a larger spot size on a downstream imager.

PRC informed XRO to follow up together.

achievements

• with help from LAS OCD, we got the PPL synchronized again with optical lock and close to the initial t0 on the sample
• we found t0 on the sample again
• collected data with magnetic field
• initial setup of damnit/amore for semi-automatized data processing

problems

• no issue besides the initial loss of PPL synchronization

Actually, it looks like the sync was lost shortly before 23h last night as the jitter went to 0fs and recovered at 1am when a new sync search probably started.

X-ray delivery

• 12.4 keV 200 pulses / train, relatively stable intensity ~0.8 mJ / pulse

Optical laser delivery

• 420 nm PP laser
• ns laser for jet imaging

Achievements/Observations

• M1 & M2 offset mirror optimized again (not really optimum but acceptable)
• NKB focus checked and defocused to have about 2um beam
• Collected a few dark runs and about 30 runs with PP laser in adaptive gain mode

Issues

• AGIPD Fixed MG mode issue
• PP-laser sync issue, but it was solved quickly, thanks to Lbsync team
• Beam pointing in the FEL Imager was quite off in the beginning of the shift 
• Hit rate too low (~0.3%)

achievements:

• inserted the magnet and measured delay scan at the maximum magnetic field with opposite directions
• data analysis showed that runs measured during the afternoon/evening led to sample degradation (the sample shows a dark spot, change in the scattering signal is also cearly visible)
• corrected spatial overlap
• moved to gresh spot and did delay scan at lower OL fluence (Tr = 35% instead of 70%)

problems:

• shortly before 23:00 the optical laser synchronization was lost for a bit more than 2 hours, then it came back shortly after 1 am at that time the PP laser phase shifter when optically lock moved from 1018 to 229.8 apparently on its own, and it was realized few hours later. We moved it back to the original value, but this was not sufficient, we had to move by several ns and we were not able to move where we wanted, Laser OCD was called a7 7:35.

X-ray delivery:

- stable at 120µJ, mostly 63 pulses

- 1:30h downtime

- checked some alternativ lens configuration to test for smallest focus

- changed nozzle of liquid jet. The old one was strongly tilted at low flow rates

- overlap between x-ray / liquid jet achieved 

- first scans from pure water at different jet distances

Problems:

- still problems with AGIPD detector movements (Motor is a state that does not exist in Karabo, only a reset on PLC level seems to solve the problem for a short time)

- x-ray beam has hit part of the shielding resulting in some damaged pixels on the AGIPD.

Laser synchronization is gone, unlocked from 04.05.2023, 22.47. E-mail was sent to lbsync-expert@desy.de and c.c. to las-op@xfel.eu.

Achivements:

-Cooling down the sample. Sample is at 14K

-Taking time resolved data at 70%  800 nm, -5 ps  - 65 ps

Problems

-Freezing of the transfer line while cooling. It seems the scroll pump was brocken. When we replace the pump cooling was OK.

achievements

• we change the DSSC timing to record the first pulse
• sample was getting damaged with 26mJ/cm2 and scattering of the sample was changed so we used lower fluence to observe t0 on the sample
• changed to 2nd mono order, 20% GATT transmission and exit slit to 0.3 mm. The scattering signal was better
• time zero was found on the sample, 4ps from coarse timing
• dataset collected at room temperature, reproducing previous results from previous beamtime
• cooling of sample set up and started

problems

• with current setting, some pixels saturate around the DSSC central hole. This limits the X-ray fluence we can use.
• sample cooling freezed

X-ray delivery

• 12.4 keV 200 pulses / train, relatively stable intensity ~0.8 mJ / pulse
• took some time in changing X-ray energy (from 19.16 keV to 12.4 keV)

Optical laser delivery

• 420 nm PP laser
• ns laser for jet imaging

Achievements/Observations

• M1 & M2 offset mirror optimized
• NKB focus roughly optimized (we used defocused X-ray beam, about 2um)
• Collected several runs for inside nozzle pump excitation project (both adaptive gain and fixed MG modes)
• Nozzle damage with PP laser tested (before and after the night shift)

Issues

• AGIPD FPGA (2nd hemisphere) issue (requied a power cycle)

Shift summary:

- get the beam with 23keV and 120µJ 

- falignment of mirrors m1 and m2 on the pt stripe at 23keV

- irst time lens alignment with CRL1 and CRL2, get beam size of 5µm at sample position for users

- took data for the calibration of the AGIPD detector quadrants with LaB6 and Al targets

- set-up trigger of in-vacuum camera and ns-laser to match x-ray arrival time

- could not move the AGPID detector

Beamline status:

- Lenses insert, DN500 closed, AGIPD HV off, Feedback running with 5 pulses and increased attenuation (2mm Si in XTD6 ATT and 0.8 Si OPT ATT additional).

Achivments:

- X-ray and Laset spot size calibration

- Course timing check

- Adjusting the DSSC distance

Problems

- Problems with DSSC data recording. It seems like DSSC dont see the first x-ray pulse. It makes offlin analysis tools to give an error.

SASE1 status:

First shift switchover this week at 23h from FXE (19.5 keV) to SPB/SFX (12.4 keV) with issues. 
No immediate lasing at 12.4 keV with standard procedures / files, then tuneup using FEL imager (CBor) in multibunch. Wrong pointing (far off up in vertical).
Recovered lasing by 23h55 with 1 mJ at 12.4 keV at 10 bunches. Handover to SPB by midnight.

Diagnostics:
XTD2-XGM stayed with HAMPv during the photon energy change, which turned out fine, but the signal would be non-linear in multibunch
operation with many bunches, thus switch to XGMDh (HAMPv power remains turned on).
Procedure practiced with BKR-crew. BKR will switch back to HAMPv when switching back to FXE / 20 keV.