Beam is back. Current status:

SASE1 (SPB/SFX)

• 2.72 mJ, 352 bunches/train, 6 keV

SASE2 (MID)

• 880 uJ, 1 bunch/train, 8 keV

SASE3 (SQS)

• 4.56 mJ, 1 bunch/train, 400 eV (3.1nm)

20h16: beam down in all beamlines due to a gun problem
20h50: x-ray beams are back
Shortly later additional 5 min down (20h55 - 21h00) for all beamlines, then the gun issue is solved.

After that, SA1 and SA3 are about back to same performance, but SA2 HXRSS is down from 130 uJ before to 100 uJ after the downtime.
Additionally, MID informs at 21h07 that no X-rays at all arrive to their hutch anymore. Investigation with PRC.

At 21h50, all issues are mostly settled, MID has beam, normal operation continues.
Further HXRSS tuning and preparation for limited range photon energy scanning will happen in the night.

Broken Bridges

Around 21h20 the XPD group notices that several karabo-to-DOOCS bridges are broken.
The immediate effect is that in DOOCS all XGMs in all beamlines show warnings
(because they don't receive important status informations from karabo anymore, for instance the insertion status of the graphite filters nrequired at this photon energy).

PRC contacts Tim Wilksen / DESY to repair these bridges after PRC check with DOC, who confirmed that on karabo side there were no issues.
Tim finds that ALL bridges are broken down. The root cause is a failing computer that hosts all these bridges, see his logbook entry;
https://ttfinfo.desy.de/XFELelog/show.jsp?dir=/2024/47/22.11_a&pos=2024-11-22T21:47:00
That also explains that HIREX data was no longer available in DOOCS for the accelerator team tuning SA2-HXRSS.

The issue was resolved by Tim and his colleagues at 21h56 and had persisted since 20h27 when that computer crashed (thus 1.5h downtime of the bridges).
Tim will organize with BKR to put a status indicator for this important computer hosting all bridges on a BKR diagnostic panel.

Broken Radiation Interlock

Beam was down for all beamlines due to a broken radiation interlock in the SPB/SFX experimental hutch.
The interlock was brocken accidently with the shutter open, see https://in.xfel.eu/elog/OPERATION-2024/203
Beam was down for 42 min (from 3h00 to 3h42) but the machine came back with same perfomrmance.

SA1 Beckhoff issue

SA1 blocked to max. 2 bunches and SA3 limited to max 29 bunches
At 9h46, SA1 goes down to single bunch. PRC is called because SA3 (SCS) cannot get the required >300 bunches anymore. (at 9h36 SA3 was limited to 29 bunches/train)

FXE, SCS, DOC are informed, DOC and PRC identify that this is a SA1 Beckhoff problem.
Many MDLs in SA1 are red across the board, e.g. SRA, FLT, Mirror motors. Actual hardware state cannot be known and no movement possible.
Therefore, EEE-OCD is called in. They check and identify out-of-order PLC crates of the SASE1 EPS and MOV loops.
Vacuum and VAC PLC seems unaffected. 

EEE-OCD needs access to tunnel XTD2. It could be a fast access if it is only a blown fuse in an EPS crate.
This will however require to decouple the North branch, stop entire beam operation for SA1 and SA3.
Anyhow, SCS confirms to PRC that 29 bunches are not enough for them and FXE also cannot go on with only 1 bunch, effectively it is a downtime for both instruments.

Additional oddity: there is still one pulse per train delivered to SA1 / FXE, but there is no pulse energy in it ! XGM detects one bunch but with <10uJ.
Unclear why, PRC, FXE, and BKR looking into it until EEE will go into the tunnel.

In order not to ground the magnets in XTD2, a person from MPC / DESY has to accompany the EEE-OCD person.
This is organized and they will meet at XHE3 to enter XTD2 from there.

VAC-OCD is also aware and checking their systems and on standby to accompany to the tunnel if required.
For the moment it looks that the SA1 vacuum system and its Beckhoff controls are ok and not affected.

11h22: SA3 beam delivery is stopped.
In preparation of the access the North branch is decoupled. SA2 is not affected, normal operation.

11h45 : Details on SA1 control status. Following (Beckhoff-related) devices are in ERROR:

• SA1_XTD2_VAC/SWITCH/SA1_PNACT_CLOSE and SA1_XTD2_VAC/SWITCH/SA1_PNACT_OPEN (this limits bunch numbers in SA1 and SA3 by EPS interlock)
• SA1_XTD2_MIRR-1/MOTOR/HMTX and HMTY and HMRY, but not HMRX and HMRZ
• SA1_XTD2_MIRR-2/MOTOR/* (all of them)
• SA1_XTD2_FLT/MOTOR/
• SA1_XTD2_IMGTR/SWITCH/*
• SA1_XTD2_PSLIT/TSENS/* but not SA1_XTD2_PSLIT/MOTOR/*
• more ...

12h03 Actual physical access to XTD2 has begun (team entering).

12h25: the EPS loop errors are resolved, FLT, SRA, IMGTR, PNACT all ok. Motors still in error.

12h27: the MOTORs are now also ok.

The root causes and failures will be described in detail by the EEE experts, here only in brief:
Two PLC crates lost communication to the PLC system. Fuses were ok. These crates had to be power cycled locally.
Now the communication is re-established, and the devices on EPS as well as MOV loop have recovered and are out of ERROR.

12h35: PRC and DOC checked the previously affected SA1 devices and all looks good, team is leaving the tunnel.

13h00: Another / still a problem: FLT motor issues (related to EPS). This component is now blocking EPS. EEE and device experts working on it in the control system. They find that they again need to go to the tunnel.

13h40 EEE-OCD is at the SA1 XTD2 rack 1.01 and it smells burnt. Checking fuses and power supplies of the Beckhoff crates.

14h: The SRA motors and FLT are both depending on this Beckhoff control.
EEE decides to remove the defective Beckhoff motor terminal because voltage is still delivered and there is the danger that it will start burning.

We proceed with the help of the colleagues in the tunnel and the device expert to manually move the FLT manipulator to the graphite position,
and looking at the operation plan photon energies it can stay there until the WMP.

At the same time we manually check the SRA slits, the motors are running ok. However, removing that Beckhoff terminal also disables the SRA slits.
It would require a spare controller from the labs, thus we decide in the interest of going back to operation to move on without being able to move the SRA slits.

14h22 Beam is back on. Immediately we test that SA3 can go to 100 bunches - OK. At 14h28 they go to 384 bunches. OK. Handover to SCS team.

14h30 Realignment of SA1 beam. When inserting IMGFEL to check if the SRA slits are clipping the beam or not, it is found after some tests with the beamline attenuators and the other scintillators that there is a damage spot on the YAG ! See next logbook entry and ATT#3. This is not on the graphite filter or on the attenuators or in the beam as we initially suspected.
The OCD colleagues from DESY-MPC and EEE are released.
The SRA slits are not clipping now. The beam is aligned to the handover position by RC/BKR. Beam handover to FXE team around 15h.

Damage on YAG screen of SA1_XTD2_IMGFEL

A damage spot was detected during the restart of SA1 beam operation at 14h30.

To confirm that it is not something in the beam itself or a damage on another component (graphite filter, attenuators, ...), the scintillator is moved from YAG to another scintillator.

ATT#1: shows the damage spot on the YAG (lower left dark spot, the upper right dark spot is the actual beam). Several attenuators are inserted.
ATT#2: shows the YAG when it is just moved away a bit (while moving to another scintillator, but beam still on YAG): only the beam spot is now seen. Attenuators unchanged.
ATT#3: shows the situation with BN scintillator (and all attenuators removed).

XPD expert will be informed about this new detected damage in order to take care.

Beckhoff communication loss SA1-EPS

12h19: BKR informs PRC about a limitation to 30 bunches in total for the north branch.
The property "safety_CRL_SA1" is lmiting in MPS.
DOC and EEE-OCD and PRC work on the issue.

Just before this, DOC had been called and informed EEE-OCD about a problem with the SA1-EPS loop (many devices red), which was very quickly resolved.
However, "safety_CRL_SA1" had remained limiting, and SA3 could only do 29 bunches but needed 384 bunches.

EEE-OCD together with PRC followed the procedure outlined in the radiation protection document 
Procedures: Troubleshooting SEPS interlocks
https://docs.xfel.eu/share/page/site/radiation-protection/document-details?nodeRef=workspace://SpacesStore/6d7374eb-f0e6-426d-a804-1cbc8a2cfddb

The device SA1_XTD2_CRL/DCTRL/ALL_LENSES_OUT was in OFF state although PRC and EEE confirmed that it should be ON, an aftermath of the EPS-loop communication loss.
EEE-OCD had to restart / reboot this device on the Beckhoff PLC level (no configuration changes) and then it loaded correctly the configuration values and came back as ON state.
This resolved the limitation in "safety_CRL_SA1".

All beamlines operating normal. Intervention ended around 13h30.

Beckhoff communication loss SA1-EPS (again)

14h00 Same issue as before, but now EEE cannot clear the problem anymore remotely.
An access is required immediately to repair the SA1-EPS loop to regain communication.
EEE-OCD and VAC-OCD are coming in for the access and repair.

PRC update at 16h30 on this issue

One person each from EEE-OCD and VAC-OCD and DESY-MPC shift crew made a ZZ access to XTD2 to resolve the imminent Beckhoff EPS-loop issue.
The communication coupler for the fiber to EtherCat connection of the EPS-loop was replaced in SA1 rack 1.01.
Also, a new motor power terminal (which had been smoky and removed yesterday) was inserted to close the loop for regaining redundance.
All fuses were checked. However, the functionality of the motor controller in the MOV loop could not yet be repaired, thus another ZZ access
after the end of this beam delivery (e.g. next tuesday) is required to make the SRA slits and FLT movable again. EEE-OCD will submit the request.

Moving FLT is not crucial now, and given the planned photon energies as shown in the operation plan, it can wait for repair until WMP.
Moving the SA1 SRA slits is also not crucially mandatory in this very moment (until tuesday), but it will be needed for further beam delivery in the next weeks.

Conclusions: 

In total, this afternoon SA1+SA3 were about 3 hours limited to max. 30 bunches.
The ZZ-access lasted less than one hour, and SA1/3 thus didn't have any beam from 15h18 to 16h12 (54 min).
Beam operation SA1 and SA3 is now fully restored, SCS and FXE experiments are ongoing.
The SA1-EPS-loop communication failure is cured and should thus not come back again.
At 16h30, PRC and SCS made a test that 384 bunches can be delivered to SA3 / SCS. OK.
Big thanks to all colleagues who were involved to resolve this issue: EEE-OCD, VAC-OCD, DOC, BKR, RC, PRC, XPD, DESY-MPC

Timeline + statistics of safety_CRL_SA1 interlockings (see ATT#1)
(these are essentially the times during which SA1+SA3 together could not get more than 30 bunches)

12h16 interlock NOT OK
13h03 interlock OK
duration 47 min

13h39 interlock NOT OK
13h42 interlock OK
duration 3 min

13h51 interlock NOT OK
13h53 interlock OK
duration 2 min

13h42 interlock NOT OK
15h45 interlock OK
duration 2h 3min

In total, this afternoon SA1+SA3 were about 3 hours limited to max. 30 bunches.
The ZZ-access lasted less than one hour, and thus SA1/3 together didn't have any beam at all from 15h18 to 16h12 (54 min).
SA3 had beam with 29 or 30 pulses until start of ZZ, while SA1 already lost beam for good at 13h48 until 16h12 (2h 24 min).
SA3/SCS needed 386 pulses which they had until 11h55, but this afternoon they only got / took 386 pulses/train from 13h04-13h34, 13h42-13h47 and after the ZZ.

Status

All beamlines in operation.
The attachment ATT#1 shows the beam delivery of this afternoon, with the pulse energies on the left and the number of bunches on the right.
SA2 was not affected, SA1 was essentially without beam from 13h45 to 16h15 (2.5h) and SA3 didn't get enough (386) pulses in about the same period.
Beam delivery to all experiments is ok since ~16h15, and SCS is just not taking more pulses for other (internal) reasons.

Beam delivery Status well after tuning finished (which went faster than anticipated).

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. 

SASE1 bunch number was reduced to 10 pulses for no obvious reason. 

Traced it back to a malfunctioning of the watchdog for the solid attenuator (see attached error message)

Deacttivated the watchdog for SASE1 solid attenuator. Re-activated it again.

Issue: SASE1 (SPB?) was requesting 200 pulses at 6 keV with full power with all solid attenuators in the beam. This was a potentailly dangerous situation for the solid attnenuator (!)

After that the team left to go home. Nobody is available at FXE.  Set pulse number to 1.

Checked status of solid attenuator. Seems that plate 1&2 have some vertical cracks (see attached picture)

11:15 SASE1/SPB called that they observed and issue with the SASE1 XGM/XTD2: about every 35 seconds the power reading jumps from 4 Watts to zero and back. It seems to be related to some automated re-scaling of the Keithlyes, which coincides. The fast signal and downstream XGMs do not show this behavior. The concern is that this may affect the the data collection later today. 

12:15 The XGM expert was informed via email, however, there is no regular on-call service today. If this cannot be fixed in the next few hours, the PRC advises to use in addition the reading of the downstream XGM for data normalisation. 

13:15 Theo fixed the problem by disabling auto-range. Needs follow-up on Monday, but for this weekend should be ok. 

Yesterday two motors of the SASE2 seeding mono were damaged. The mono was exchanged in the afternoon and pumped down. Currently, an issue with the vertical cystal motion is being investigated.  The vacuum improved much faster than expected after this intervention, so the hope is that the tunnel can be searched soon and electrons could go through SASE2 already this afternoon. Watch for updates in the program for SASE2 in the DESY logbook under 'Schedule'.     

In SASE2 undualtor cell 10 has issues. Suren K. will do a ZZ at 11:30 to fix it (if possible). Estimated duration: 1-3 hours. 

Update 12:30: The problem is more severe than anticipated. Suren needs to get a replacement driver from the lab and then go back into the tunnel at about 14:00 

In principle, the beam could be use dby HED until 14:00

Update 13:30: Beam was not put back, because energizing and de-energizing the magnets would take too much time. Whenever Suren is ready, he will go back into XTD1 and try to fix the problem. 

Udate 17:30: Suren and Mikhail could do the repair and finish now th zz. A hardware piece (motor driver) had to be exchanged and it turned out that the Beckhoff software on it was outdated. To get the required feedback from Beckhoff took considerable time, but now everything looks good.  

The control rack of the soft mono at SASE3 has some failure. Leandro from EEE will enter the XTD10 at 12:00. 

Beam will be interupted for SAS1 and SASE3.

Estimate to fix it (if we are lucky) is one hour. 

Udate 12:30: Problem is solved (fuse was broken, replaced, motors tested)

Update 13:30: Beam is still not back, because BKR has problems with their sequencer

SASE1: Solid attenuator att5 is in error. When it is tried to move it out, the arm lifts, but does not reach the final position before the software time-out. We  increased the software time-out from 4 seconds to 7 seconds, which didn't help. We suspect that there is a mechanical problem that prevents the att5 actuator to reach the out position. 

SPB states that it is ok to leave the attenuator arm in over the weekend, because they run mostly detector tests and don't require full intensity.  

Late shift 07.02.24
Laurent, Martin

Continued with laser preparation

• optimized SHG
• changed lens to f = 600 mm
• knife edge scans
• found optimum lens position (95 mm) for w0 = 70 um
• fluence characterization --> up to more than 2 J /cm^2
• Coarse timing
• Fine timing

night shift summary 07.02.24

Andreas, Giuseppe

program was to determine horizontal an vertical beam size and then create some single laser shot patterns to determine fluence settings for LIPSS.

PROBLEMS:

• knife edge insensitive to beam sizes smaller than 20um due the large beam jitter of the FEL.
• moved to the camera and curved gratings but then encountered vacuum issue with scroll pump down since noon 07.02. fixed by replacing scroll pump.
• useful camera data could not extracted as we cannot control the TPI shutter and have multiple exposures of the camera. STPulser Macro need to be fixed.
• SCS_XTD10_TPI/DCTRL/SHUTTER in the SCS topic is not found after shutting device down when tracking down device issues.