• upper and lower branch of SDL aligned
  • beamsizes and angular mismatch characterized
• vacuum leak of flight path fixed
• side view microscope re-aligned
• problems with replaced MPC diamond detector. issue with in-vacuum cabeling suspected
• misconfigured timing of AGIPD fixed
• splitting ratio of SDL detuned while HXRSS intensity decreased significantly. Possibly correlated.

With the current HXRSS intensity and focussing, we have insufficient conditions to take data for the experiment. We decide to vent the sample chamber and try to fix the malfunctioning diamond detector instead of taking data over night. HXRSS should be improved tomorrow morning and the SDL possibly realigned afterwards.

• stable HXRSS delivery at 8.99 keV, 1 bunch. XGM intensity during the day decreased from 750 uJ to 600 uJ.
• Vacuum in sample chamber stabilized with cold trap and full beam path opened to AGIPD and endstation
• Again problems with smaract stages in DES, but imager in a good position to continue.
• First scattering data recored from water jet. Unknown, bimodal intensity distribution
• Focus characterization of SDL lower branch with knife edge, X-ray eye and SAXS speckle data. Larger (>10 um) as compared to direct beam with same focussing setup.
• Clear influence of splitter insertion on beamsize observed. Beam is smaller without splitter crystal.
• Current status: Alignment of upper branch unfinished, X-ray eye inserted, sample chamber vented

For the next shift:

• Finsish alignment of upper branch
• Characterize both beams in size with Xray eye. Try if slightly different lense combinations or M2 bender settings improve the situation.
• Overlap both beam on the sample
• Possibly insert upstream pinhole just in front of jet to clean up and ensure overlap
• Take data, enjoy

Activities:

• continued tr-RIXS scans
• tried to find ways to mitigate the energy drifts of the mono (see below)
• confirmed in user data that the FEL-PPL timing was not changing (see below)
• setting up for tr-RIXS at beginning of night shift

Problems:

• the mono energy has been drifting, presumably due to warming of the grating.
• automatic correction of the elastic line in the RIXS data was not working reliably
• we suspected a timing drift, but it seems that the monitor (photodiode + oscilloscope) itself is drifting. That's a new one.

The intensity of the Seeding decreesed from 850 uJ to 550 uJ during the time between 20:00 and 02:00.

The Spectral purity also got worst, the beam in HIREX looks to have more SASE shoulders.

Between 18 and 20 we show a prossible transiant signal, PPL, of the lower branch. But a problem with the monochromator in the MID opt Hutch trigger the valve to close. After we where not able to see the signal possible effect of laser or X-ray inestabilities.

Problems with the liquidjet, the nozzel got clogged.

Started the aligment of the upper branch of SDL

Stable HXRSS delivery with >800 uJ, 1 bunch, 8.99 keV.

Re- Alignment of X-ray beam performed.

-Beam position defined for sample interaction in SAM CAM1. Do not touch SAM CAM1

-X-ray beam (unfocused and focused) is now going through LIC & 45 deg mirror. Updated M2 feedback setpoint.

-CRL2 has been aligned to the new position.

-Lower branch SDL aligned. Not on Sample interaction point.

-LIC mirty moved out -63 mm (in at 6 mm)

Status now:

We moved lower branch out. CRL2 left in.

We have left the direct beam (no branch) on the X-ray eye and inline microscope.

We have left some diamond in the OPt Hutch Att for running  feedback and HIREX

To do:

- Bring both branches to the sample interaction point in SAM CAM1.

- Aligment upper branch

- Spatial overlap laser and X-ray

- temporal overlap with diode (from laser and lower branch?)

- Beamsize analysis of both branches

Activities:

• Found coarse and fine timing between FEL and PPL at 266nm
• Set up for tr-RIXS during the night

Problems:

• 2 fastADC channels appear to be dead.
• Optical locking of the PPL syncronisation system took a very long time (> 30 minutes)

Achievements

• Found RIXS signal from liquid jet
• Measured static RIXS and PFY-XAS spectrum of Co(cp)(CO)2

Problems

• hRIXS detector has a data latency issue and images were not being recorded in the DAQ. This required ~2-3 hours to solve plus time lost during night shift.

Plan for Next Shift

• find temporal overlap between X-ray and laser

• HXRSS delivery, 600 - 700 uJ, 1 bunch, 8.991 keV. Pedestal visibly in HIREX, not checked with MID spectrometer yet.
• beamline aligned and beam brought to popin imager
• struggle with jet pumping, to be continued
• beam brought into experimental hutch, first rough alignment of reference samples and cameras
• Epix flight path leaked and window re-glued

SCS could only use two pulses, because the SXP imager was still in the beam and SXP shutter open. 

I removed the SXP imager, so SCS can now get the full beam. The SXP shutter is still open and SXP instrument contacted via email to find out, if the shutter is intentionally open. 

21:13: SXP confirmed that they will close the shutter tomorrow. The imager was just forgotten in the beam. 

In order to optimise the performance of SASE2 self seeding, a stronger compression setting is required. 

The RC proposed to increase the time window between SASE2 and SASE1/3 to avoid performance degradation and cross talk effects on SASE1/3. 

I discussed with SCS and FXE instruments and there seems to be nothing against moving the time trigger by 30 micro seconds later, as proposed by BKR. 

The agreed bunch train lengths can be still achieved with the new setting. The change will be implemented now (Tue 14:45)

The longitudinal feedback on SA1/3 was swicthed off by mistake over night. When it will be switched on, the beam may wiggle a bit an SA1+SA3 for short. 

We agreed with SCS and FXE that this will be done today at 11:30 

The SA2 XTD1 XGM is current offline since Saturday morning.

Yesterday, Friday, it already started to present communication problems ( https://ttfinfo.desy.de/elog/FileEdit?file=/XFELelog/data/2023/10/10.03_a/2023-03-10T19:06:29-00.xml&xsl=/elogbook/xsl/elog-fileform.xsl&mode=edit )  and today it became clear a Hard drive is broken and need to be exchanged.

Theo M. and Fini J. are preparing to enter tunnel around 13:00. PRC has informed BKR, RC and HXRSS team. We do not expect to have the problem fixed until the end of the Saturday.

In parallel, beam permission to South Branch was removed due to the lack of communication to the XGM. PRC suggested RCs to disable the corresponding Big Brother rule in order to keep beam permission to proceed with few activities until the ZZ takes place, what was done by machine RPO.

*** Update 14:50:

The ZZ was successful and the colleagues managed to exchange the hard drive and reinstall the software. The XGM shall be working again but it will be monitored in the coming hours.

Special thanks to Theo M., Fini J., Soeren G. and Dey-IT colleagues for the precious volunteer work on Saturday.

X-ray delivery stable in intensity, 1300-1400 mJ at 8150 eV SASE.

user experiment 3430 (Zastrau / Mishchenko)

Horizontal jitter compensated with intermediate focus (by overfocusing with CRL in XTD1, and focus on target with CRLs in HED OPT.
Beam drifts compensated by M2, M3 mirror feedback

RELAX laser shots on 10 um Cu foils, last 12 h pumping a Cu 22+ resonance K line. probing laser plasma at 0, 5, 10, 20 and 50 um spatial offset

Completed our data set. We now have 100fs resolved 2d transmission images and K-resonance from +1 ps to -100 ps delay time.

Successful user experiment.

Achievements:

1. Continued measuring time-resolved and static RIXS on water (run table in elog entry #103)

2. Periodically checked spatial overlap and BAM compensator in-between measurements.

3. Refilled and changed cold traps when necessary.

Problems:

1. Some icing issue, solved by changing the nozzle.

X-ray delivery

• 9.3 keV, 202 pulses, 564 kHz, intensity slope was fine

Optical laser delivery

• 800 nm, 68 pulses, 188 kHz. stable delivery
• ns laser for illumination

Achievements/Observations

• Continue nanofocusing setup with pump-probe experiment
• Continue Collecting TR-SFX data

Achievments

-RIXS scans at different delay times and x-ray energies

-Cross check fine timing

Problems

-Nozzle was frozen. Pump was in error state.

Achievements:

- we replaced broken SMA cable, and added an angle-connector at sample holder to aid the sample rotation when moving diagnostics to the flat jet

- we double-checked coarse timing and x-ray beam size

- we found t0 on SiN

- setting up RIXS with time delay steps for the night shift program

X-ray delivery

• 9.3 keV, 202 pulses, 564 kHz, intensity slope was fine

Optical laser delivery

• 800 nm, 68 pulses, 188 kHz. stable delivery
• ns laser for illumination

Achievements/Observations

• Continue nanofocusing setup with pump-probe experiment
• Continue Collecting TR-SFX data

Issues

• uTCA timing was shifted about 3 ns against X-ray and PP-laser

Achievements:

- Improved the vacuum of the chamber slightly

- Found the spatial overlap between FEL and jet

- Found the spatial overlap between FEL and PP laser on pBN (but may not be the same on liquid jet)

Problems:

- Beam loss for 6+ hours, from 23.00h to 5.15h due to fuse tripping in the laser system of the electron gun

- While fixing the beam loss, the machine seemed to have trouble with timing. So if fine timing can't be found, perhaps it's worth it to check rough timing again.

- The rough pumps in the room are full of water. We solved this by taking 2 rough pumps and connecting them directly to the chamber.

- The antenna cable is too bulky. So the sample plate should only be rotated to -90 deg (-358.65 actual), as rotating the other way will severely tilt the sample plate.

X-ray delivery

• 9.3 keV, 202 pulses, 564 kHz, intensity slope was flat

Optical laser delivery

• 800 nm, 68 pulses, 188 kHz. stable delivery
• ns laser for illumination

Achievements/Observations

• Continue nanofocusing setup with pump-probe experiment
• Continue Collecting TR-SFX data

Issues

• Run_Controller problem still persists, it stopped without any action from us