Issue with SA3 Gas attenuator (SA3_XTD10_GATT) - SOLVED

Dear all,

after the reported issue by SQS colleagues regarding the impossibility to inject Argon, and after a first remote evaluation, we (VAC) have entered XTD10 to assess the status and verify the most probable working hypothesis: a manual valve in the supply line was closed (otherwise as expected). Joshua and Benoit confirmed it and the showstopper is now gone. The system is back to normal and standard operation can be resumed in any moment. 

A small remark: as Argon (or any other gas different from Nitrogen) is not the default operation mode, it is important that if needed, there should be an explicit request during the preparation of the operation tables with XO. This would help to avoid this kind of situations. Unfortunately sending a short notice e-mail just before the next run is clearly not recommended.

With best regards.

SASE3
Open Issues:
- currently it is not possible to change the number of pulses because of Instruments beam permission interlock
Done:
- VSLIT was calibrated with diffraction fringes (it was off by 41 microns, the bottomo blade encoder was recalibrated to compensate this error)
https://in.xfel.eu/elog/XRO+Beam+Commissioning/319
- various setting points were checked at 20 mrad using mirror switch, no particular problems found
https://in.xfel.eu/elog/XRO+Beam+Commissioning/310
https://in.xfel.eu/elog/XRO+Beam+Commissioning/306
- ESLITS width was measured using diffracted beam. No Calibration was applied, we will discuss with instruments if this is needed/wished
https://in.xfel.eu/elog/XRO+Beam+Commissioning/323
https://in.xfel.eu/elog/XRO+Beam+Commissioning/324
https://in.xfel.eu/elog/XRO+Beam+Commissioning/325
- ATTENTION: SQS ans SXP ESLITS motors are now moving in the opposite direction as before (please look at the updated picture on the scene). Software limit switches are real limits: do not deactivate them
SCS ESLIT was already in this way: now all the ESLITs are configured similarly (no Elmo controllers anymore)
- SRA calibration was recalibrated
https://in.xfel.eu/elog/XRO+Beam+Commissioning/313
- FEL imager cross adjusted to GATT
https://in.xfel.eu/elog/XRO+Beam+Commissioning/307

SASE2
Open Issues
- HED Mono1 still not going through until HED popin. Paralleism of crystals achieved. Transmission is ok until Beam Monitor but not further.
Beam height was checked but the problem remained
Done:
- M3 mirror realigned, Euler motion roughly calibrated. 
ATTENTION: Old saved values are no longer usable. "XRO setpoints" must be used as a starting point for further alignment
- Positions C and E were saved
- The fast flipping positions were almost found, see here: https://in.xfel.eu/elog/XRO+Beam+Commissioning/322
Unfortunately, beam was suddenly off and the procedure was not complete
- No particular problems found

SASE1
- FXE and SPB trajectory rechecked, no particular problems found

ATTENTION:
- M1 & M2 motors were found with wrong scaling factors (since some times). They are corrected while maintaining the mirror positions. (Most affected was M1 vertical motors which is rarely used).  
- saved positions are using the "fast flipping option" meaning that you can switch between the two only using M2 RY
https://in.xfel.eu/elog/XRO+Beam+Commissioning/283
https://in.xfel.eu/elog/XRO+Beam+Commissioning/282
- CRL1 motor calibrations were lost, and restored from 6th Dec. In case if there are further issues, contact Control. 

Starting shift with mirror motor calibration:

- beam is centered on FEL imager

- pblm in XTD9 is inserted

We removed both silicon solid attenuator and pblm

Starting shift with mirror motor calibration:

- found solid attenuator 0.5mm silicon inserted

- beam is centered on FEL imager

- pblm in XTD9 is inserted

We removed both silicon solid attenuator and pblm

- M3 TX moved to 0 in steps of 1 mm and beam on FXE Pop-In corrected with M3 RY (+) and M2 RY

- Started calibration with M3 Rz in steps of 0.5 (+) and corrected with M2 RY and RZ to find a position with a minimum of parasitic motion

- Iterations with M3 TY

- CRL 3 and 4 were inserted (using find target)

- The backlash correction was disabled

- Curve for M3 Rz position with Ry correction done. M2 RY/RZ corrections to move beam up and down to have it on the screen

- Curve for M3 Ty position with Ry correction done.

- Curve for M3 Rx position with Ry correction done

M3 vertical motors calibrated to 0

Dear all,

we calibrated the mirror vertical motors to their geometrically neutral.

Please be aware that saved values for beamline settings may no longer be valid. This mainly applies to the vertical motor positions, but will have an impact on Tx and Ry values as well.

As starting point, use XRO Optics Setpoints 'C' - this setting was last used to bring beam to SPB

We fine tuned geometry parameters for linear effects on X motion (parallel offset) for all three mirrors.

dTz was corrected for M2 and M3 to -6.5mm (same geometry)

dTz was corrected for M1 to +6mm

for M2 we were able to do a parabola scan Y motion to check for lrTz

lrTz was then corrected to -433mm

correction in the same direction for M3 did not yield better results

Final mirror positions at HED - see picture

We plan to put the piezos of M2 off, in the (unprobable) case that this is the reason of the "jumps" in SASE3 trajectory.

Therefore, I measured the change on RY and RZ motors, to correct all the positions

Fig 1: initial position, Motors Ry=10.5425 and RZ=-14.7200  Piezo Ry =5 and Rz=5

Fig 2: Ry is compensated, Motors Ry=10.4990 and RZ=-14.72  Piezo Ry =0 and Rz=5

Fig 3: Rz is compensated, Motors Ry=10.4990 and RZ=-14.7574  Piezo Ry =0 and Rz=0

Differential values: RY needs to be adjusted by -0.0435 and Rz by -0.0374

Beam is now aligned back to HED for hand-over to Naresh (see picture)

points achieved:

-vibometer measurements on M2 at high energy, 2,1 and 3 mrad setting

-tried again to find beam through pblm grating, but no success

this morning, ZZ was done together with Sylvia Huynh (EEE) to solve softmono pre-mirror motor issue https://redmine.xfel.eu/issues/177392

The issue was solved and also mechanical functionality of the stage was checked.

After ZZ, the beamline remained interlocked. Hutches will be searched and closed tonight to allow final checks on Tuesday

What has happened:
During euler motion calibration of M1, we were driving the vertical motors by a few mm back and forth. At some point, the Rz motor went into error, as we attempted to go further in negative direction. Resetting the axis several times did not solve the problem. The vertical motors were then moved to 0 position. DOC was called and helped to overwrite some parameters that triggered the error.
When resuming the calibration routine, the beam suddenly got lost and the vacuum interlock triggered V0 to close. Vacuum in M1 recovered quickly, but on M2 popIn, only the direct beam could be seen. At this point, the conclusion was that one of the motor connections must have come loose, which caused the vacuum event and removed M1 from the beam.

It was then decided, that we break the interlock, vent the chamber and re-connect the motor if possible.

The situation we found was the following:
-Rz connection lead-screw to bellow was detached
-mirror sitting on the mirror holder
-significant InGa spillage on chamber bottom, window flanges opposite to the mirror AND a lot of drops on the mirror surface

Pictures are attached.

Intervention:
The lead-screw and nut were exchanged. There was significant wear on the bearing plate, connecting the lead-screw to the bellow.
When trying to install the new lead-screw with a spare bearing plate, it was found that apparently the thread on the bellow side was deformed as well, and the spare part did not fit to the thread. Since the old bearing plate was the only possible way to connect the lead-screw to the bellow, it was cleaned, lubricated and re-used. The position was manually adjusted around 0 position (66,7mm protrusion) and the motor connected.

Recommendations:
- since the damaged bearing plate was re-installed, it should be avoided to move Rz. The motor should be permanently interlocked and only operated with absolute care for initial alignment.
- the mirror surface is severely contaminated with InGa, it must be checked if a position with acceptable beam can be found (only to be done by XRO as this needs Rz to be moved)
- the affected bellow has to be exchanged to facilitate replacement of the damaged bearing plate. As this requires the mirror chamber to be opened, this only makes sense in connection with replacement of the mirror + cleaning of the chamber.

X-ray delivery

• 0.25nC, 14 GeV, rep rate 2.25 MHz, 9300 eV, 1 to 100 pulses, ~2000 uJ
• M1 and M2 mirrors are aligned and beam trajectory to SPB.

Goal

• Commissioning of the Gotthard-II 25um MHz detector on SA1-HIREX.

Achievements

• Aligned the HIREX using bent diamond crystal C110 and no gratings used.
• 2D camera(Bragg/photonic science) aligned and spectral data is collected.
• Trigger delay scan of Gotthard-II detector. The best trigger delay setting was found at 1952637.
• Calibration Pipeline is established and can load/inject the constants
• Online preview of Gotthard-II corrected data is successfully tested and commissioned.
• successfully able to load calibration constants and dark runs in myMDC.
• Successfully able to start the calibrated data after completion of runs in myMDC.
• Calibration/corrected and dark data reports are successfully generated in the proposals
• New filter stage commissioned and tested. Updated the positions in the MDL.
• Intensity scan output for strips 2150 and 2151, obtained varying the SA1 diamond attenuators. I_0 is calculated integrating the output from strip 2000 to strip 2300.
• Different gain setting data was collected.
• Gotthard-II tested and commissioned with different rep. rate: 4.5 MHz, 2.25 MHz, 1.125 MHz, 0.5 MHz. The test was sucessfull and we can record spectrum for different rep. rate.
• There are no visible aritfacts around the gain switching region, and the correction seems to work well.
• spectral data is collected with 2.25 MHz with pulses 2, 30 and 100.
• Attachment 1: Fisrt results from Gotthard-II with spectral data in MHz rep rate.

Issues:

• Calibration pipeline of pulses/train (ASSEMBLE_STREAK) couldn't able to instance. DRC and OCD DA group helped to fix (Thank you)
• Adhoc data sources were added in SA1 COMM with support from DRC and CTRL (Thank you)
• beam lost at ~12:30hr today due magnets issues and till now no beam. Unable to continue the rest of the program planned for commissioned of the Gotthard-II.

Thanks to Marco, Jiaghuo, DRC(Monica), CTRL OCD (Andrea), DA OCD (Karim) for there support and help.

EPS issue for Transmissive imager SA1 (OTRC.2615.T9) w.r.t Operation eLog #96

The motor screen positions w.r.t. the EPS switches had been realigned (last Wednesday 8th May), tested today (14th May) and the EPS is again enabled for the different beam modes. All is back to normal.

Concerning damage of the SA1 FEL imager, Operation-2024 eLog #206

The screen position of the YAG screen - when pressing the screen selection button - has been moved by 1 mm so that the damaged area is out of the field of view, see attached screenshots (damage visible under visible light exposure).
The screenshots show the cross-hair, i.e. its nominal beam position and the circular damaged area at its original position of the screen and the new position.

More information on the damage can be found in the damage report, entry #35:
https://docs.xfel.eu/share/page/site/xfelwp74/document-details?nodeRef=workspace://SpacesStore/fd862f30-c6a3-4a5e-9a65-817cbcebb2d9
Also, there is a comment in ttfinfo: https://ttfinfo.desy.de/XFELelog/show.jsp?dir=/2024/47&pos=2024-11-19T09:39:31

Dear MID colleagues, Svitozar (PRC), Bolko and Shan (RCs),
This morning we faced the situation where MID was limited to 400 pulses (mode M) via the EPS signals. The current RF window set at the machine allows to the requested 450 pulses.
The limiting conditions were the inserted graphite filter (#2) and the diamon screen at the MID Pop-in (#17). After a discussion with experts (and thanking Naresh, Wolfgang and Andreas), both conditions in EPS mode F (see attached) are now disabled, as the current SA2 beam offer safe condition for both devices.
This special situation with disabled EPS signals in mode F is in place until Tuesday 05.Nov as MID will stay at ~12.28keV and with HXRSS (500-600uJ). Please note that in case of either a change in photon energy, substantial increase of photon flux, longer SA RF window or the wish to insert YAG screen at the SA2 Pop-in, these two mentioned conditions have to be enabled again at the SA2 EPS Mode F prior these actions take place.
After the beamtime ends on Tuesday 7AM, either me, Naresh or the PRC will make sure these two EPS conditions are re-enabled.
In case of questions please do not hesitate in contacting me.
Best wishes,
Frederik

**Update Mon 15:00: The beamtime delivery to MID is extended up to Tuesday 9AM. At this moment the EPS signals will be enabled again by Frederik W.-F.

The cross on the FEL imager, which we use as a reference for BKR crew, is not centred on the GATT aperture. when was this changed, and why?

att. 1 and 2 show the current position (the saturated image aids the positioning of the GATT aperture).

att. 3 is from two weeks ago. then, the cross was centred on the GATT aperture.

it is not clear why, but the beam position on BIU2 has changed over time, even more since we checked last. it is off in both directions

we see the GATT aperture projection drifting, so it is a change in the beam transport, not in the source.

see the beam, cut by the DIAG1 slit, compared to the cross it should be centred to.

the motor encoders in the beamline have not changed since the beginning, when the beam was pointing correctly.

we needed SASE1 to be set to 0 pulses briefly to check alignment in our experiment.

The FXE control hutch was empty. we could not reach either Chris nor Mykola by phone. The XFEL_StatusPublic shows that the FXE shutter is closed (we can also see the exp hutch door open from outside the control hutch).

Neither PRC nor BKR had any information about the FXE status.

We discussed with PRC and concluded that they are likely not using the beam, so in agreement with PRC we went ahead and got BKR setting SASE1 to 0 pulses at ~10:20. After few seconds, we got BKR setting SASE1 back to 30 pulses.

edit: PRC got in contact with FXE. Turns out they were (are) working in their ILH. we have a contact procedure for the next occasions now.