SA3 SCS exit slit: the upper blade was detached from the motor and fall into closed position. Maurizio V. and F. Wolff-Fabris tried to move it out of the beam by placing spacers to hold the blade up.

Bottom blade was moved down with the motors. Currently both motors are disconnected.

*** Update 14.02 10AM:

This morning the exit slit was clipping the beam. Another ZZ by M. Dommach, M. Petrich and F. Wolff-Fabris was done to move up the top blade by a further 8mm. 

After that intervention SCS confirmed to see the beam at the Pop-in and at the experimental hutch.

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.

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 

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)

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. 

Reply to elog103:

Spoke with Machine RC Thomas Wamsat and SQS.

Machine RC has some ideas to try. SQS have agreed that they can give 30 min for the machine to optimize the intensity.

SA1 has no impact while the machine trying to improve the power for SA3.

Update at 21.17hr

Machine RC has optimized for higher pulse intensity for SQS from 900uJ to 1600uJ. But still, the problem reported in elog103 exists, However, SQS can work now and overnight.

Thanks to Thomas Wamsat for his effort to support.

Machine RC Raimond informed PRC that there is an issue with the A4 module that needs to fix to have a continuous operation. To fix this they need 20 min.

Agreed with all instruments (SPB, SQS, and HED) that at 13:30hr machine will take over the beam for 20 min.

Update: 13:55hr

Machine finished fixing the issue for the A4 module and beam handover to all beamlines.

TUE 08:30AM:

The SA3 Cell 17 & 18 Phase shifters do not move and encoders are damaged. A ZZ is needed to exchange the encoders. Instruments are informed and access will take place Tuesday morning. Machine has separated the north branch.

*** Update 10:20AM:

ZZ is finished; beam in North Branch to restart soon.

Changed EPS Interlock condition for SPB_XTD9_IMGPI/SWITCH/SCREEN_OUT

SPB/SFX called DOC this morning for being limitied to two pulses by the EPS (Instrument should have called PRC instead)
After tracing the issue to the SPB_XTD9_IMGPI/SWITCH/SCREEN_OUT switch SPB/SFX decided to take this imager out of the interlock, confirming on camera that no screen was inserted.
EEE and DOC investigated the issue without conclusion https://redmine.xfel.eu/issues/151238
 

SPB_XTD9_IMGPI/SWITCH/SCREEN_OUT disabled in EPS Mode30 and Mode400
for todays SPB/SFX shift we'll keep it like this, PRC will check with FXE when they take over at 23:00

Issue with SA1_XTD9_PBLM and it is stuck.

Hi All,

After discussion with SPB, they will slightly move the PBLM screen where they don't see any distortion in the beam and are willing to continue to work till Monday. 

The conclusion from EEE (Leandro) and DOC is that from PLC everything looks fine and it might be with mechanics for this we need to physically look at the device. 

As SPB can work like this till Monday. I proposed on Tuesday with someone who has knowledge of PBLM device can organize the ZZ

Next week Jan is PRC

Dear FXE colleagues,

There is an issue with SA1_XTD9_PBLM and it is stuck. Please when you use the beam in the night, coordinate with SPB first. or call PRC no. 9-4800

- Received a call from machine RC (Sergey Tomin)

- There is an issue with DOOCS to Karabo bridge, Tim and DESY experts are looking into this and came to the conclusion that it can't be resolved now and need more time something like 1 week. (probably next week). Due to this PySpectrometer for SA3 is not available, as SQS would like to set up a spectrometer to measure pulse duration. However, it can work in Karabo and take data.

FXE (Fred) confirmed that they don't use beam for night shifts from Friday to Sunday.

The machine tuning over the night had not yet accomplished fully satisfactory beam conditions mainly at the high photon energies for SA1 and SA2,
therefore tuning continued during WED morning.
Beam was handed over to SCS (SASE3) at 9h with about 2.4mJ at 2.5 keV.
Beam was handed over to FXE (SASE1) at 13h with about 530uJ at 19.5 keV.
Tuning for MID (SASE2) at 23 keV is agreed to continue until 14h, currently at a level of 120 uJ. 

SASE1 status:

First shift switchover this week at 23h from FXE (19.5 keV) to SPB/SFX (12.4 keV) with issues. 
No immediate lasing at 12.4 keV with standard procedures / files, then tuneup using FEL imager (CBor) in multibunch. Wrong pointing (far off up in vertical).
Recovered lasing by 23h55 with 1 mJ at 12.4 keV at 10 bunches. Handover to SPB by midnight.

Diagnostics:
XTD2-XGM stayed with HAMPv during the photon energy change, which turned out fine, but the signal would be non-linear in multibunch
operation with many bunches, thus switch to XGMDh (HAMPv power remains turned on).
Procedure practiced with BKR-crew. BKR will switch back to HAMPv when switching back to FXE / 20 keV.

MID reports an observation that is particular to the operation at the currently high photon energy of 23 keV

MID inserted the XTD6-MID-preabsorber and assumed that it completely stops the beam.
They acquired AGIPD detector images as dark frames but were surprised to still find some weak background signal (not dark).
The explanation by PRC and XRO is that the purpose of the pre-absorber is to protect the shutters against potential
damage and not to entirely stop the beam like a radiation protection shutter itself.
The pre-absorbers contain diamond and B4C but no tungsten. The calculated transmission of the pre-absorber at 25 keV is 4%.
3rd harmonic of the FEL (here at 69 keV) is on the order of 1%, and MID uses the mirror coating
stripes for high photon energies, thus transmitting well these high photon energies.

As another result, the apparent beam size observed on the downstream imagers can be more complex to understand:
MID actually also reports that the beam size appeared larger in the afternoon than in the morning,
depending on the insertion status of the pre-absorber and the lenses.
The scintillation efficiency of the YAG screens is known to be high also for hard x-rays beyond 30 keV.
Additionally, the CRLs focus the various harmonics differently. When CRL1 is set to focus the beam,
it will likely defocus higher harmonics yielding a larger spot size on a downstream imager.

PRC informed XRO to follow up together.

Info from XRO (Maurizio Vannoni) to PRC concerning tunnel access request #152936 (Inspection and repair of SQS ESLIT)

- The ZZ-access will be done by Marc Planas, Massimiliano Di Felice, and Idoia Freijo.

- They will start their access between 9h00 and 9h30 and end their access by 12h30.

https://redmine.xfel.eu/issues/152936

UPDATE 11h45: ZZ-access is completed, beam is back in operation.

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

HED reported that they are unable to go 352 pulses and while changing/dailing the no. of pulses in the bunch Pattern it is showing the EPS is limited to 300 pulses. It seems on the SA2_MAIN scene the link for bunch Pattern apparently using the macros scene, which is preventing it from going to 352 pulses. Now I have updated the link with a new scene of MDL for the bunch pattern. In the attachment, you will find both scenes. One toward the left is MDL bunchPattern configurator and one towards the right is Macros bunchPattern. 

Now the issue is solved. 

thanks

Naresh

PRC wk 22

- SA2 photon beamline

Today morning found the CRL1: 5 and 6 arm and Pop-in 45-I are still IN. I have retracted them.

SASE2 vacuum incident

7h10 : MID informs PRC about a vacuum incident in the SASE2 tunnel which tripped the beam. Instructed to contact directly VAC-OCD

8h26 : VAC-OCD informs that investigation is ongoing, but beam can be delivered. This kind of trip usually occured rarely
           and usually can be reset by VAC. Apparently the source of the issue is at the XTD1 solid attenuators.

8h36 : MID confirms to PRC that already 3 trips occcured but the experiment so far can continue. Beam delivery continues.

10h11 : VAC-OCD informs that now there is a bigger more wide-spread issue with the XTD1 vacuum system
           and beam operation is stopped for at least 1 hour. VAC group and DOC are working on the issue.

11h : It turns out that the vacuum bellows of the 2.4mm diamond attenuator in SA2_XTD1_ATT has a leak, which is worse and
         not acceptable in terms of vaccuum in the extracted state (bellows elongated) but less severe in the inserted state (bellows compressed).

12h33 : info by VAC: issue is temporarily solved by blocking the 2.4mm diamond arm in the IN position. Must clarify today how to proceed further.
          The vacuum issue thus is temporarily solved, beam permission is back,

12h38 : Beam coming back to MID. MID can work today with this ATT always inserted, but not for the weekend.