Activities:

• correctly positioned magnet
• moved detector upstream and found small beamstop
• Recorded SAXS
• Started tr-SAXS

Problems:

• The SAXS images from laser-excited samples showed unexpected variation between different size rings, central point (ie not a ring) and no scattering. 

Activities:

• Investigated SAXS scattering instability and found it to come from the pointing variation of the PPL
• Recorded microscope images of the PPL spot of the pBN to quantify the pointing for different spot sizes
• Enlarged the beam and measured pumped SAXS. Results seem better than before.

Problems:

• PPL pointing is not stable enough for consistent pumping effect in the probed area.
• Sample scanner x motor went into error due to interaction with the magnet and had to be coaxed back into operation.
• FEL down with cryo problem.

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.

Achievements

• Beam transport
• Coarse and fine timing
• XAS on Co
• Aligned HSLIT, pinhole, camera beamstop
• Characterize FEL beam size and position on curved grating
• PPL Power measurement
• Fluence scan on sample of optical laser and FEL to determine good conditions
• Prepared for night shift time-resolved measurements

Problems

• No major issue

achievements:

- finished SAXS data recording till 8am on time-resolved skyrmion nucleation and field dependence

- the setup is sensitive to beam transport drifts due to the closed hor-SLIT and the pinhole in FFT. were able to recover beam intensity by simple adjusting the horizontal pitch of M2 ~1.5urad change during th enight 

- first initial test runs on holography performance under giving beam settings. source stability seems to work nicely. afterburner will be important for cicurlar polarizations 

problems:

no issues

achievements:

- finished SAXS data recording till 8am on time-resolved skyrmion nucleation and field dependence

- the setup is sensitive to beam transport drifts due to the closed hor-SLIT and the pinhole in FFT. were able to recover beam intensity by simple adjusting the horizontal pitch of M2 ~1.5urad change during th enight 

- first initial test runs on holography performance under giving beam settings. source stability seems to work nicely. afterburner will be important for cicurlar polarizations 

problems:

no issues

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.

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

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:

• 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.

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.

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

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

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

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

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:

• measured delay scans on 16 nm samples at different magnetic fields (4 runs) before the problem below appeared

problems:

• scroll pump of the FFT degraded, rough vacuum got worse, this led to pump in error state and interlock valves. The scroll pump was replaced, vacuum re-established, but we could not see any signal from the samples, only diffuse scattering. We thought this was due to ice frozen on the samples when the pressure increased. We warmed up the cryostat, verified that the conditions of the samples are fine again, and finally started cooling down again.

achievements

• exchanged He dewar and managed to cool down the sample again after vacuum issue last night
• started collecting additional scattering data with alternating magnetic field on large nanoparticles sample

problems

• no issues

Achivments:

-Move DSSC closer to the sample.

-Measure delay scans for opposite magnetic field.

Problems:

-No major problems