Vacuum issue at HED

At 18:26 the vacuum failed in the HED CRL3 chamber in the OPTs hutch. The vacuum failed in the section and tripped the valves in the OPT hutch; it went from 1e-8 to 5 mbar in seconds. The leak is confined to the CRL chamber -- the sections upstream and downstream are not compromised and still have good vacuum. Therefore we believe the leak to be in one of the bellows of the CRL arms. This needs to be investigated tomorrow by the technicians.

The late shift is cancelled since we cannot continue with lens alignment. The night shift may continue with work on the DiPOLE laser - up to them.

BKR is informed that they may use the time for tuning.

06:45

X-ray delivery

• 13.6 keV, ~1.6 mJ and up to 352 pulses at 1.1 MHz.
• Beam down from 10:30 to 19:00.

Optical laser delivery

• 800 nm, 50 fs, 1 to 176 pulses at 564 kHz pumping TOPAS at 475 nm.
• Stable delivery.

Achievements/Observations

• PP laser and X-ray spatial and timing overlap.
• Collected data for ~7.5h.
• Very stable sample delivery.

Achievements
-Check XAS and static RIXS after the beam was back
-Do the warm up cycle to remove ice from the sample surface
-Check coarse timing after the beam drop
Problems
-Could not see the fine timing signal so far

Milestones:
*Finish measurement program on the STO sample at room temperature
*Check mono fpitch and energy rocking curve
*Darks for AGIPD and JF
*take out mono, CRLs etc from the tunnel

Beam delivery:

*Beam was not available from 11:30 to 19:30. Returned to good conditions back at  ~2mJ, 10.5keV, 15bunches

Morning shift Summary 22.10.2023

Achievements

• Checked beam alignment and overlap

• confirmed sample integrity with static rixs on other sample locations
  Problems

• beam down after 11 am. No chance to resume till at least 18:00h

X-ray delivery

• 13.6 keV, ~1.6 mJ and up to 352 pulses at 1.1 MHz.
• Beam down until around 1PM.
• After agreement with FXE, we could collect data until midnight.

Optical laser delivery

• 800 nm, 50 fs, 1 to 176 pulses at 564 kHz pumping TOPAS at 475 nm.
• PP laser down for ~4h. Facility cooling water for the AMPHOS chiller was down, solved by LAS and TS OCD (controller had to be replaced).

Achievements/Observations

• PP laser and X-ray spatial and timing overlap.
• Collected pump-probe data ~1.5h until PP laser down, then dark data on a different sample and then again ~1.5h pump-probe at the end of the shift

Issues

• Beam down in the morning.
• PP laser down in the evening.

Achievements:
-Collecting TR-RIXS data for different fluencies and delay range
Problems
-No major problems

# Morning Shift Summary 21.10.23

Ben, Eugenio

Achievements
* Found maximum of CDW with theta scan
* set up for time-resolved measurements

Problems
* FEL was down most of the shift due. Beam delivered around 12:30

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

X-ray delivery

• 13.6 keV, ~1.6 mJ and up to 352 pulses at 1.1 MHz.
• Beam down at 22:47, not recovered before the end of the shift. Otherwise stable delivery.

Optical laser delivery

• 800 nm, 50 fs, 1 to 176 pulses at 564 kHz pumping TOPAS at 475 nm.
• Intensity modulations through the burst during the second half of the day. Solved by LAS OCD. Otherwise stable delivery.

Achievements/Observations

• Remounting of diagnostics stack under the injector.
• PP laser and X-ray spatial and timing overlap.
• Collected data from noon until beam down towards the end of the shift.

Issues

• Discrepancies between delay calculated by OpticalDelay device and motor encoder position appearing from time to time.
• Karabo GUI crashed twice when after pressing enter while editing a table.

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

X-ray delivery

• 13.6 keV, ~1.7 mJ and up to 352 pulses at 1.1 MHz

Optical laser delivery

• PP laser, 1 to 202 pulses, stable delivery except for the down time of ~1h

Achievements/Observations

• user sample data collected for ~1.5h
• PP laser timing scans done
• new adapter for the screens holder designed, machined and installed

Issues

• sample was growing on the adapter, preventing data collection
• new adapter is too far downstream, partially shadowing sample diffraction on the lower corners of the detector
• PP laser down for ~1h

X-ray delivery

• 13.6 keV, ~1.8 mJ and up to 352 pulses at 1.1 MHz

Optical laser delivery

• PP laser, amphos laser computer in error for ~2h

Achievements/Observations

• x-ray beam aligned and focused
• PP laser optimization done
• AGIPD background reduced to 1-2 photons diffuse scattering

Issues

• Beam down ~2h
• PP laser down for ~2h
• AGIPD tripped due to pressure spike, currently all off

Shift summary (p4239)
Achievements:
- HXSS beam at 10.5 keV at 400 uJ pulse energy
- MID beam alignment to DES
- aligned DES spectrometer for C220 reflection on Gotthard and flight path;
Issues:
-    Seeding crystal was stuck in parked position and could not be inserted back (late evening); to be investigated via ZZ access tomorrow

X-ray delivery

• 13.6 keV, ~1.6 mJ and up to 202 pulses at 0.5 MHz

Optical laser delivery

• PP laser, stable delivery

Achievements/Observations

• User sample delivery tested
• M1 and M2 aligned
• x-ray beam aligned and focused
• PP laser spatial and temporal alignment done
• AGIPD background reduction to be optimized: still one photon diffuse scattering and ten photons scattering on the top right quadrant

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

• 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?