Achievements

1. Start cooling down the sample
2. Align the beamline and deliver the beam into the sample
3. Performed knife edge scans and enlarge the beam horizontal size to 350 um
4. Tuned the VHM bending by checking the hRIXS resolution
5. Performed energy calibration on the 1000 l/mm grating
6. Check XAS and RIXS of the NdNiO3 sample at 20 K, normal incidence, and peak A

Problems:

1. Nothing of note

Shift Plan:

1. Check static RIXS at a few different configuration
2. Check damage threshold with x-ray and laser
3. Find spatial and temporal overlap between laser and x-ray
4. Performed pump-probe XAS and RIXS

Achievements:

1. Set up PP laser, find spatial and temporal overlap between FEL and PP laser
2. Optimize MCP and HAMP settings for good XAS signal
3. Find time zero from XAS on sample and optimize for XAS delay scans at 40 deg incidence angle
4. Take a fluence series on XAS delay scan from about 0.1 mJ/cm2 up to 2.5 mJ/cm2

Problems:
Nothing of note

Achievements:

1. Replaced focusing lens of PP laser and measured focus with knife edge, focus is about 720 micron vert. & 600 horizontal. Horizontal x-ray spot size is 220 micron
2. Adapted fluence calibration for the new spot sizes
3. Optimized spatial and temporal overlap with new lens
4. Performed optical and x-ray intensity & sample damage tests. We found that up to 15% GATT and up to 50% laser power are okay to use, without altering the sample.
5. We started to collect hRIXS data at positive (1ps) and negative (-2ps) delays.

Problems:

1. Few beam dumps.
2. BAM scene not working
3. The new (?) centroiding function produces spectra with different intensity for acquisitions with the same settings. The old algorithm seems to work well.

Achievements:

1. Performed tr-RIXS on peak A, B, and C at 2.4 mJ/cm^2
2. Performed tr-XAS on peak A at 3 fluences
3. Performed tr-RIXS on peak A at 4 mJ/cm^2

Problems:

1. BAM delay line compensator was not working due to incorrect macro. DOC and LM fixed the issue.
2. Delay line scan of hRIXS camera was not working as it was still configured for Viking. MT fixed the issue.
3. The new centroiding algorithm (provided natively by the 4137 kernel) is not consistent with integration mode. For the time being, we use an older, manually configured centroiding algorithm developed for a previous user beamtime.
4. tR-XAS results show large changes, but these large changes were not reflected in tr-RIXS.

Achievements:

1. tr-RIXS at 4 mJ/cm2 for energies A, B, C, and D (pre-edge)
2. Checked and optimized FEL alignment, t0 and overlap with PP laser after reset of machine synchronization

3. Long delay scans for Peak A and C, up to 100 ps
   Problems:

4. Need to reset machine synchronization by BKR

5. Camera scene got stuck, was resolved by DOC

Achievements

1. Acquired tr-RIXS data with 4.0 mJ/cm² laser power for 21 delays between -2 and +10 ps at 853 eV. including static XAS and dark hRIXS runs. Totally collected 210 minutes of data i.e. 10 minutes per delay
2. Acquired tr-RIXS data with 4.0 mJ/cm² laser power for 21 delays between -2 and +10 ps at 853.44 eV. including static XAS and dark hRIXS runs. Totally collected 210 minutes of data i.e. 10 minutes per delay

Problems:

1. hRIXS camera number of readout ports was set to 1, increasing the readout time. Set it to 2.
2. Elastic line drifted about 40 meV over 3 hours (first and last trRIXS run at 853)

Achievements:
1. Finalized tr-RIXS series at 1.74 mJ/cm2
2. Checked FEL alignment
3. Started fluence series for tr-RIXS on peak C, completed: 1, 1.5 and 2 mJ/cm2

Problems:
1. We noticed that calculator for PP laser fluence was not giving a correct value. The formula was corrected and the older logbook entries need to be checked. We start to use the "new values" from now on.
2. XAS processor get stuck and was restarted
3. left PC (pcx30525) got stuck and had to be restarted
4. hRIXS camera scene got stuck, so that it would not operate the PP laser delay stage. Help from DOC.
--> Solution: shutdown and reinstatiate device: SCS_HRIXS_DET/MDL/CAMERA_SHUTTER

Shift Plan:
Continue fluence series for: 0.5, 2.5, 3 mJ/cm2. Decide about further data points.

achievements:

- we found optimum hRIXS settings for 1020 eV but moving the detector arm

- we found optimum hRIXS settings for 920 eV but moving the detector arm, and then grating pitch and detect arm

- energy calbibration for 920 eV

problems:

- lost internect connection around 6 am

- PI-MTE3 camera claims an exposure of 30 sec but in reakity it"d more lik r13 sec.

- if FEL intensity goes to 0 i spikes, the jupyter notebook give errors, referring to objecests ofdifferent sie.

plans:

-

Achievements

• Determined temporal overlap between the X-ray and laser
• measured Ti L-edge XAS and RIXS on samples for Asamara beamtime

Problems

• No problems

Plan for Next Shift

• Confirm spectrometer resolution at the O K-edge following spectrometer rotation
• Transfer user samples into XRD Chamber
• Check X-ray damage on user samples and begin user program

Achievements:
- Optimized hRIXS settings for OK edge at 145 deg scattering angle, resolution of about 50 meV
- Transferred the user sample
- Prepared for delay scans on fluorescence signal from YBCO

Problems:
- There was no internet connection at XFEL and DESY for some time
- hRIXS camera goes frequently into error
- XRD motors (STY) go frequently into error

Next steps:
- Find time zero on fluoresce signal from YBCO, test the same for the samples
- Test PP laser damage threshold

Shift summary 07.09.2023

Achievements:
1. found t0   on LSCO x=0.15 at pre-peak O K edge
2. fluence dependence at dt = 130fs, laser-on-off XAS => laser power at 50%
3. static XAS on the three samples x=0,.15, .4 aorund the pre-peak
4. setting for pump-probe: 1.1 MHz 520 pulses at 100% Transmission, PPL at 50%

Problems: 
10:10pm loss of optical sync on PP laser. realized before starting time-resolved experiments. coarse timing requried !

Program for the night shift:
reestablished timing
resume experimetns, i.e. time-resolved signal on sample (XAS) then start time-resolved RIXS.
 

Achievemnets

• Characterized the X-ray and laser danage on the STO2LNO2

Problems

• Cound not find fine timeing from XAS measurements performed on the sample
  • MCP sees 266 nm PP laser
  • SiN mesaurement not successful so far. It is possible that there is an issue with the SN membranes on the sample holder

Plan for next shift

• Find fine timing
• conclude damad sutdy of sample.

Around 6:55 there was a power glitch. Power in the experimental hutch and rack room went down in SASE3, error message in Xray interlock system and no power for PP laser.

During morning TS turned the power on and interlock issues were solved by DESY. SCS could restart large part of SCS systems, however got help of DOC only after 2:30p.m. Similarily, PP laser was needed help of DOC and got this help only around 2p.m. The afternoon shift was mainly bringing the instrument in operation with helps of DOC. Around 9p.m. we realized that PP laser is not in operational state because of large fluctuations, this was not communicated to SCS at all. After calling the Laser group, SCS was told that the laser group will work on recover of the laser on Sunday morning. Without laser we could not continue user program, therefore  at least 24h of user operation were lost.

Achievements

• Characterized optical laser spot at sample

Problems

• FEL beam had very unstable intensity and spectrum. As a result no useful data could be collected during the night
  • FEL pointing seemed to be stable on all tunnel imagers. The issue was communicated to BKR, and they said that things looked fine from there perspective.
  • Large fluctuations in spectral distrubtion at SCS spectrometer were observed. See video at https://syncandshare.xfel.eu/index.php/s/emtwonCsQJJqpz6
  • Oth-order beam on SCS pop-in showed large intensity fluctuations with ~50% of the time showing no beam at all

# 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

# Morning shift summary

Giuseppe, Martin

* achievements
- continued tr-RIXS measurements
- good beam conditions
- added new alarms to give warning if parameters are wrong for certain measurement type
- created new karabo device to calculate the fluence and train-averaged pulse energy in nJ from pulse-resolved HAMP values (see new scene in Main)

* problems
- none

Achievements

• Tested MCPs and APD for XAS
  • Both MCPs give a good XAS spectrum with no amplification, but small MCP requires higher bias voltage
  • No fluorescence signal observed on the APD
• Measured XAS of both samples
• Measured static RIXS of under-doped sample

Problems

• None

Plan for next shift

• Sample alignment (half clip+diffraction)
• Switch AFS laser to burst mode and find timing

Night shift summary 21.10.2023

Achievements

• Found T0 on SiN, but the response is very slow (~10 ps).
• Azimuth (phi) scan
• Start of theta scan with optimized phi

Problems

• Even after finding T0 on SiN, still could not find T0 on sample with XAS
• Beam down at 5:25