Photon beam delivery status:

- Machine informed that beam will be handover to instruments SA1 (SPB/SFX) and SA3 (SXP) at 18.30hr

- Machine needs more time for SA2 and the next update will be at 20hr.

This message has been communicated to instruments.

- Machine updates;

Saturday 1:30 hr Cold compressor failed. The initial estimation of downtime was 20 hr, later in today morning crew gave a new estimation of time of 30 hr. So the machine will be switched on and beam delivery to instruments will be tomorrow morning. Today at 3 pm, I will get more information and a clear picture of the best estimation time for beam delivery.

Naresh

Dear All,

Two important machine updates.

1) Still, the forecasted time for the start-up of the machine will be tomorrow morning.

2) After discussion with machine RC, it is confirmed that beam delivery is extended by 24 hr, so the beam is available till 7 am Tuesday morning for instruments.

Just want to point out, that this is a very exceptional case that it is extended by 24 hours as there will be a blue week(in wk 35).

The below programs have been canceled keeping in view of the user program and beam delivery is important for instruments. Sorry for this.

153339 - Euler MDL calibration for SASE2 mirrors M1, M2, M3: Antje 

158376 - Beamtime for Safety tests (HED Preabsorber): Eric

156699 - SASE3_XTD10 Virtual Spectrometer: Joakim

157789 - Chirp-dispersion short pulses study (further decoupling from SASE1): Svitozar

Stay tuned to the public display tomorrow morning for the machine's status.

thanks

Naresh

PRC wk 34

Info from MRC (Lars)

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The cryo crew reports that the cold compressor that failed is, alas!,
the new one with the magnetic bearing. They have to wait for a colleague
who is not on call to help them with the problem. We expect an update on
their further plans around noon and our status panels have been updated
to reflect that.

Cheers,
Lars

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- Due to the failure of the cryo cold compressor. The machine is down.

- Next update 9 pm today

Please do watch public display for status info.

Info from Machine RC (Lars):

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Author: Froehlich

One of the cold compressors has stopped working around 2:00 on Saturday morning due to a problem with the new motor (with magnet bearing). Since no beam operation is possible anyhow, the cryo team and machine coordination have decided to start necessary work on cryo plant stages 3&4 already on the weekend, in parallel to troubleshooting the motor problem.

All XFEL shifts up to Monday 7:00 are canceled. The morning shift on Monday will supervise the already scheduled access for the repair of A16 and, if possible, the restart of the linac.

This elogbook entry was sent to following experts:
Photon RC mailing list RC mailing list xfel-operation-board@desy.de

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Direct link to e-logbook entry:
https://ttfinfo.desy.de/XFELelog-sec/show.jsp?dir=/2023/36/09.09_M&pos=2023-09-09T14:51:07

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Achievements:

• measured the new sample, Silane, with different time delays

Problems

• Tuning of SASE2 led to a 50% decrease in the SCS XGM intensity without affecting the SASE3 intensity. It also caused a jump in the BAM value

Ealier shift members managed to get a good quality image on Optique Peter by imaging the sample plane to the Optique Peter with downstream nanofocus (CRL4b). The quality is far superiour compared to the one with upstream nanofocus, which does just a projection of sample (backlight). The decision is to stay with the downstream CRL. They had a few full power shots. The problem of reading Zyla data when rotation = 0 is solved by Olly. He put the script in the shared folder. 

As no laser shots during the night shift, the plan for the night shift was to align as many AWE samples as possible so that we can shot tomorrow morning.

We successfully aligned samples (about 20 samples) which are in A-2 slot. Then, very, very, unfortunately, when we went to the A-1 samples, the top part of FSSS bump the ILM and we could not recover it. We have two choice now for the morning shift; whether we shot currently aligned samples (without checking the laser focal spot and timnig - those are should not be so wrong as it was checked late last evening by the late shift members); or, open IC1 and realign the ILM...

%%%%

18 Feb 2023, 00:33  Aligned the sample A2-E5. The laser comes from the top. What we see here is the 10 um thick Al top layer. The CH (~500 um thick) is below the Al on the screen, which is almost fully transparent for the x-ray beam. Att. 1

18 Feb 2023, 00:56 In order to optimze the rotation of the sample (so that the thickness projetion on the Optique Peter is minimum), we used the Hexapod "w". Unfortunately, this motor value is not saved onto the sample position table. Therefore, all previously saved positions are not valid any more. The current "w" value is -5.300 (att.4). We should not touch this value any more.

Att. 5 is the previously saved sample positions. We will delete many of these positions as those are not valid any more.

18 Feb 2023, 00:58 We aligned the wire to FSI, ILM and Optique Peter. Att. 2 and 3.

18 Feb 2023, 03:56 There was a collision with the ILM, when going to the top row on the target (AWE A2-B1), targets no longer visible on ILM. Wire also shows O(10um) offset on OptPeter. Previously aligned targets will be off.

18 Feb 2023, 04:23 We realign the wire, reproducible with a 20um offset applied in hex_x and hex_y (saved on the target positions)

18 Feb 2023, 04:24 We start a scan of ILM position to try and recover FoV (5 x 5 mm window, 2D scan, 250 um steps). No success; we couldn't find the flatfield. One suggestion is to shoot currently aligned targets blind.

18 Feb 2023, 05:00 Enter the hutch A.12 to connect the Timepix3. Radiation dose search.

18 Feb 2023, 05:20 Carsten optimized the CSLIT.

18 Feb 2023, 06:00 Moto worked on PAM. Found the time = 0  at 'spectral' encoding. Detail is in the corresponding eLog.

8.2 keV, 750 uJ. 

Short summary

- Optimize the downstream nanofocus CRL to image the sample to our detector (optique Peter) - successful)

- Then we put a upstream nanofocus to focus on our sample location to directly image the x-ray spot. We scan Z to get the beam profile at different Z. - successful

- It appears that we couldn't get the best focus. The upstream CRL should move further toward the sample by a couple of cm. 

- We tried doing the edge scan. Scan tool clash the DAQ and we couldn't run the data. 

- Then, we used Extra-metro to do the edge scan. It was ok, but the observed values are scattered and normalization seems not working properly. Should analyze in more detail. Runs are taken 

- The spatial resolution of our imaging system seems to be about 2 um, most likely limited by the point spread function of the scintillator (mfp of excited electrons).  

- Then we put the Optique Peter further downstream by 2 m to gain magnification and better resolution. It appears that in order to image the sample to the Optique Peter at the end of the hutch, we need to move the downstream CRL toward upstream by about 4 cm. 

Details. 

19 Feb 2023, 23:33 Handover done. Although PAM work was suggested, Toma switch off the laser. So this task is impossible. Also, we do not have a flat-field to align samples. 

19 Feb 2023, 23:34 Put a Siemens Star in (pos. #25). No image is seen on the Optique Peter. We moved FSSS Y and X to find. We moved about 100-200 um. 

19 Feb 2023, 23:41 CRL4-B 'in' position was AXIS21 = 27.4 (different from yesterday). We moved out by moving 

19 Feb 2023, 23:42 Move out the CRL4-B. The beam center of mass is upper part of the slit. Touch M3 pitch via piezo. Siemens star image at the beginnig: Att.1.

19 Feb 2023, 23:52 Move Z of CRL4-B. Initial position: 52.77. Move by 5 mm. Image quality clearly worse. We move 2 mm steps. Each step, we see the difference in contrast.

19 Feb 2023, 23:59 Now, scan with 1 mm steps. The conclusion is that 51.77 +/- 2 mm is the best.

20 Feb 2023, 00:16 Go to the free space. Attenuate the x-ray beam further by x100 (T = 1e-4). Put CRL4-A. 

20 Feb 2023, 00:20 It appears that we did not need to add the attenuator. So, stay as it was: ~1%

20 Feb 2023, 01:30 Finished scanning Z. See ID47. The best spot size seems to be before the TCC even at the maximum Axis_5 position at 105 mm. 

20 Feb 2023, 01:50 We now move the CRL4-B focus to find the smallest spot. The smallest spot is found when we moved ~20 mm in Z. The smallest spot observed corresponds to 2 micron, which is probably our limitation of the imaging system, not necessarily the actual x-ray focus. See ID47 

20 Feb 2023, 02:05 Edge scan. We first put the Ni edge as suggested, but then realized that 25 um Ni at 8.2 keV only absorbs 70% of the x-ray beam (below K-edge). Therefore, we put the edge of the Si substrate of the Siemens stars. But this doesn't give a nice result. Switch to Ni mesh. Better, but the result is not convincing. 

20 Feb 2023, 03:45 Continue focus scan. See ID 47 for details. 

20 Feb 2023, 05:00 Put the Optique Peter at the end of the hutch. Initial distance = 56 cm (Att.1). Current distance 270 cm (~ 480 cm from the exit flange of IC1). 

20 Feb 2023, 05:43 Put extension flight tube 3 m (and remove the 50 cm one). Att. 2. Start pumping IC1.

20 Feb 2023, 06:00 Found Siemens star. But we reached the HW limit of the downstream CRL in order to image the TCC to the Optique Peter. See ID50. 

18 Feb 2023, 23:37 Together with the last shift members, we continued shooting laser on Cu 25 um thick wire for another 2 hours. We got excellent quality x-ray imaging with a series of time delay up to several ns (eLog ID 39).  X-ray imaging is now commissioned. The magnification was x7.5.

19 Feb 2023, 01:30 We tried to go to x20, but we couldn't find the x-ray beam. We even put the burn paper in front of the Optique Peter to verify the x-ray position, but still we couldn't see anything on the Optique Peter. Probably the x-ray was too weak. This activity was done with CRL4b "in", so the beam size was big on the Optique Peter. Next step is to remove the CRL3b and do the same exercise.

19 Feb 2023, 03:00 We switch to CRL4a (upsteam of the sample) and aligned.

19 Feb 2023, 03:30 In parallel, PAM work: added 10 mm thick SF57 on the spectral arm. Time = 0 is established for both spatial and spectral arm. See eLog ID 33.

19 Feb 2023, 06:10 Put a mesh 2000 lines and do the focal scan. 1.5 % transmission. Att.1. The focus is around Axis_5 = 95-100 mm.

9.752 keV, self-seeding, 700-800 uJ.  Intensity is very stable, ponting is also much stable than usual. very good beam.

Beamtime #3326 - Axion search.

Successfully aligned two Ge crystals to Laue conditions (Rocking curve width ~0.002 deg) . Found Laue reflections after 2 crystals on Jungfrau detector.

We realized that the Xeryon rotation stages used for rotation of stage was wrongly calibrated (1 deg was not 1 deg), which caused some confusion. But we found a workaround solution. Still, we doubt about the repeatability and stability of the stage.

The biggest issue was that we lost the Laue reflection very quickly when we put a full intensity onto the crystal. The beam size is about 500 um FWHM. The Bragg angle at the heated sample fluctuate (does not go toward a single value).

We tested several different x-ray intensities to find the optimum flux where the Bragg condition stays. It seems, if we go to 0.1% transmission, the decay time is about 20 - 30min, which may be good enough for data.

We also discussed on swiching back to SASE. As the fluctuation of the Bragg angle seems to be  < 0.02 deg, which would be covered by  the SASE bandwidth. But, that means the photon energy goes to the second crystal fluctuate, then we lose the Laue reflection from the second crystal - probably going to SASE doesn't solve the  issue. This is the current situation.

We called DOC - Optics hutch attenuation stopped working - solved. Jungfrau2 data cannot be taken by DAQ - we decided not to solve this issue as JF2 is not necessary for this beamtime any more.

During the morning shift (7am - 3pm), we couldn't take any meaningful data due to the issue of power glitch which caused the beam permission error (AIBS) and down of SASE2 Karabo / Online-GPFS due to the lack of cooling in the rack room.

During the late shift (3 pm - 11 pm), after these issues were solved thanks to PRC/DOC/ITDM/EEE at 5 pm..., we could get back in operation relatively quickly. Although there were a bunch of issues here and there (most of the devices needed to be instantiated and recover the correct parameters, loss of XGM, DAQ issue etc), Theo (XGM) and DOC helped us promptly.

Fortunately, the x-ray axis was not changed much. The beam was still exactly on the FEL imager cross. After the recovery of M2/M3 feedback (needed to recover the correct parameters which was a bit of time consuming though), the beam correctly went to the HED popin cross. The beam height at the sample location was about 30 um off in height. The temporal synchronization between the x-ray and laser was changed to about 4 ps compared to that of the morning. 

We started taking data at ~ 9 pm. Since then, until the shift handover at 11pm, users could acquire data very smoothly. They will continue acquiring data with the night shift (11pm - 7 am) members. 

Summary of today's activity:

• Beam handover ~ 3pm.
• SA2 mirror set tp B4C.
• SA2 Rough alignment to MID & HED @ ~ 2-2.5 mrad ==> img 1, 4, 5 & 6
• SA2 HED-Preabsorber position check with x-ray (working) ==> img 2 &3
• SA3 M6 mirror Switch check (seems to be working)
• SA1 rough alignment to SPB (M1,M2) at 2 mrad ==>img 7&8

Dear all,

I just got the information for BKR that due to a failed klystron we had a downtime around 8:40am this morning for about 30 mins.

Operation could be restarted successfully afterwards but with a different energy distribution than before. SASE2 has now reduced pulse energy and SASE3 got an increase.

The energy distribution from this morning will be reestablished tomorrow morning in a planned touch-up procedure tomorrow morning.

I hope that you can keep running your measurements under the new conditions. If not please do not hesitate to contact me!

Best regards

Michaela

staus of JUN16, 11:30

SA1 and SA3 have been adjusted to acceptable conditions to be compatible with simultaneus operation at SA2

tuning on SA2 is ongoing

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status of JUN16, 8:40

Update: problem is solved. Rack fuse in electrontunnel was blown. Operators are bringing the machine back up at the moment.

Afterwards (around 9pm) photons are all needed at SASE2 for tuning to full train mode.

Photons will be given back to SA1 and SA3 as soon as possible. Please encounter good beam conditions for measurements not before 10 am.

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Dear all,

please note that we have a downtime since 4am which is expected to last until 8am or longer. There are issues with the following components: magnets, BLMs, the XS1 dump-PLC etc.

The source is yet unknown and will be investigated in an access to XS1.

I will keep you informed in this channel.

Regards

Michaela

SASE3 Summary of Maintenance Period and Ramp up activities

Maintenance

- Soft Mono motions (grating horizontal and grating pitch) were cleaned and lubricated

- Vertical slit encoders were double checked (without moving them) to exclude that Karabo errors are coming from them.

- Motors of Mirrors were inspected (without dismounting) to check if some strange noise is created during motion. The SA3 M2 Tx motor was very noisy at 0.035 speed and not anymore at 0.03. 

- Settings of acceleration and velocity was optimised together with EEE (Bernard). The noise at SA3 M2 Tx was disappearing even with 0.035 speed.

- M1 and M2 chillers had service (water filling) and were then set on again before closing the tunnel. For M5 and M6, cooling is off.

- Piezo controller for M1 was disconnected and removed. Therefore, the M1 piezos are unavailable at the moment. This was agreed with the experiments after it was found some instabilities in the beam position (beam was moving by itself sometime). 

- PBLMs were checked: https://in.xfel.eu/elog/XRO+Beam+Commissioning/76

Inst Dept Ramp up

- SA3 M2 RY was not moving. This took several hours to be solved. Temprary explanation: stepcounter value changed without any physical movement of the motor and later on, encoder was thought to be wrongly calibrated and thus adjusted. As a result, the motor position is lost and needs to be fiducialised again in the alignment.

- The performance of "Closed loop" and "Backlash Correction" was tested. The result is that the TY motors need to remain in open loop and with 'Backlash Correction' activated (value 2 microns). This is increasing the reproducibility of the positioning. The other motors could be used in closed loop if required, but then the Backlash Correction has to be deactivated.

- SA3 M6 RY encoder has an incorrect calibration at the moment. Please refer to the motor position only. We will work on a solution asap.

- The vertical slits (SCS, SQS, SXP) were checked and they move correctly.

- Several positions were fiducialised, that could be used as a starting point for Instruments fine alignment:
SXP 9mrad (8.9mrad) mono he premirror 937eV 
SXP 9mrad (8.9mrad) unfocused
SCS 9mrad (8.9 mrad) unfocused
SCS 9 mrad (8.3mrad) unfocused
SQS 9mrad (8.7mrad) unfocused
SQS 20mrad (18.5mrad) unfocused

- SEPS interlock was succefully tested: https://in.xfel.eu/elog/XRO+Beam+Commissioning/112


 

SASE1 Summary of Maintenance Period and Ramp up activities

Maintenance

- MC2 library update was deployed by EEE and most of the motors were tested afterwards
- Some motors were acting strangely: https://in.xfel.eu/elog/XRO+Beam+Commissioning/82
- As a rule, the Closed Loop and the Backlash Correction are atm incompatible and therefore you have to choose one of them. When a strong reproducibility is needed, the motor should remain in Open Loop and with Backlash Correction activated (2 microns for TY and 50 microns for TX, tipically): https://in.xfel.eu/elog/XRO+Beam+Commissioning/83|
- FXE mono1 bottom crystal was exchanged, realigned parallel to the beam. Recommissioning due WK5 together with FXE
- M1 and M2 chillers had service (water filling) and were then set on again before closing the tunnel. M3 is currently with cooling off.

Inst Dept Ramp up

- Several positions were fiducialised:
SPB alignment 2.41mrad 9keV
FXE alignment 2.4 mrad 9 keV

SASE2 Summary of Maintenance Period and Ramp up activities

Maintenance

- Many vibration tests were done.

- M1 chiller had service (water filling) and was then set on again before closing the tunnel. M2, M3 cooling is off.
 

Inst Dept Ramp up

- Positions reached:
MID 2.2 mrad at 9 keV 
HED - 9keV - 2.7mrad - B4C stripe

- checks for the stripes were done:
M3 verification of coating positions and horizontality or the mirror
MID alignment Pt stripe - vertical motion of mirrors with Euler

- for the stripes, we have now a watchdog telling if the mirrors are on the B4C or the Pt stripe (see image below)

Update of the damage tests at SQS.

Yesterday (15.04) SQS staff created a focused beam on our sample using a small YAG fragment we have placed on the holder.

Due to the unusual position, the beam is full of aberrations but it looked small enough for our purpose. Estimattion of the size is difficult atm but it is our intention to measure it with imprints.

We managed to align the sample 1 (silicon, uncoated) in grazing incidence at 19 mrad and found the damage threshold at current focusing conditions at around 100 uJoule (looking on the SQS XGM).

We managed to align also on sample 2 (silicon, B$C coated) at the same grazing angle and we found a threshold at around 200 uJoule.

We started to do systematic spots at various energies, using the GATT

One difficulty is that the manipulator is not enough precise to scan several mms in grazing incidence, the sample has to be realigned along the scan and we cannot find a clear centering on the sample due to the lack of reproducibility.

In the late shift we started to do imprints to characterise the beam spot.

Overall the experiment is on a very good status. Until now, we explored only single pulse damage. Today (16.04) we will try multipulse damage and single pulse damage at 9 mrad.

 

Today we comtinued the program, changing to 9mrad amd 15mrad and doing also multipulse. We had a short interruption at around 15 to extract some samples and to realign Sample 3.

Mirror positions and beam position on the imagers for 14.8 keV SPB, 2mrad

ATTENTION: the alignment was difficult due to the strong background from SA3 with 500 pulses. For the future, maybe SA3 could reduce to single pulse during alignment of SA1. This would make the process easier.

fig1: M2 popin

fig2: M3 popin

fig3: SPB popin

fig4: beam transport overview

fig5: mirrors positions

fig6: for comparison, this is the M2 popin image when a strong background from SASE3 is coming (500 pulses, 3milliJoule, 2.1 keV)