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

Again: power outage !

As yesterday, at around 7am, power was lost in Schendfeld at SASE3. No beam permission, accelerator in TLD mode.
SASE3 has no power, TS-OCD informed and on the way. BKR informs MKK to check cooling water pumps.

PRC is requesting all involved people of yesterday to take action acoording to what happened yesterday.

Goal: Analyze and quantify the mispositioning of the new 4mm-aperture behind the undulator

Positions in tunnel:

• ABSP4.2422.SA2 = ABSP4.CELL37.SA2 L_z position 2422.558m
• Last closed undulator for this test is cell16 at 2294m (at end of segment) = SR radiation source point
• IMGTR = 2576m (BT=181.1m, PD=582.0m).
• IMGSR = 2586m (BT=191.6m, PD=591.5m).
• IMGFEL = 2637m (BT=242.0m, PD=642,8m).
• Sequence: end-of-cell16 -- ABSP4 -

Measurements:

• IMGTR : dX=15.15-8.25=6.9mm. dY=17-9.8=7.2mm. Aperture shadow mean diameter = 7.1mm
• IMGSR : Aperture shadow mean diameter = ca. 8.5 mm
• IMGFEL : Aperture shadow mean diameter = 9.0 mm.
  The handover cross is at dy = +1.0mm (up) and dx = -2.6mm (left) relative to the apparent center of the aperture shadow.

Comments to the screenshots:

• The handover cross on the IMGFEL cannot be seen simultaneously with the weak SR background because it has the color scaled to high intensity beam.
• The FEL beam spot is almost perfectly centered on the handover cross.

Calculations:

Conclusions:

The 4mm aperture is misplaced by 0.97mm (x) and 0.37mm (y).
It should be moved dx = -0.97mm and dy = 0.37mm, or the FEL has to be made on a different trajectory.

Dear all,

please find here a summary of the status on this critical topic provided yesterday evening (around 19:15) by Zunaira Ansari (extract from her e-mail).

"Dear colleagues,

Thank you very much for your cooperation. SEPS interlock tests are completed in all SASEs except SASE3. AIBS interlock tests are complete in all hutches.

SASE3 SEPS interlock will be tested on Monday the 30th of January strating from 9a.m.

I kindly request the use of the SQS control hutch for the testing.

All SASE3 hutches will be interlocked on Monday morning.

@Maurizio and Bernard/ Nerea: Could you please be present during the testing? IIt will be much appreciated.

I would very much like to thank Eric, Nerea and especially Bernard for helping with the interlock tests today.

Best regards,

Zunaira

Achievements:

1. tr-RIXS at 4 mJ/cm2 for energies A, B, C, and D (pre-edge)
2. Checked and optimized FEL alignment, t0 and overlap with PP laser after reset of machine synchronization

3. Long delay scans for Peak A and C, up to 100 ps
   Problems:

4. Need to reset machine synchronization by BKR

5. Camera scene got stuck, was resolved by DOC

Achievements:
1. Finalized tr-RIXS series at 1.74 mJ/cm2
2. Checked FEL alignment
3. Started fluence series for tr-RIXS on peak C, completed: 1, 1.5 and 2 mJ/cm2

Problems:
1. We noticed that calculator for PP laser fluence was not giving a correct value. The formula was corrected and the older logbook entries need to be checked. We start to use the "new values" from now on.
2. XAS processor get stuck and was restarted
3. left PC (pcx30525) got stuck and had to be restarted
4. hRIXS camera scene got stuck, so that it would not operate the PP laser delay stage. Help from DOC.
--> Solution: shutdown and reinstatiate device: SCS_HRIXS_DET/MDL/CAMERA_SHUTTER

Shift Plan:
Continue fluence series for: 0.5, 2.5, 3 mJ/cm2. Decide about further data points.

This has several implications:

- ALL PREVIOUSLY SAVED RY POSITIONS ARE OBSOLETE!

- Ry values seem to have changed by a factor of 1000

- Accelleration and decelleration have been reduced significantly.

- MOTOR WILL STILL MOVE FOR SEVERAL SECONDS WHEN PRESSING 'STOP'

-Motor velocity has been reduced

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)