X-ray delivery

• 1-165 pulses, 1.1 MHz - 56.4 kHz, upto 350  uJ @ 50 pC

Optical laser delivery

• ns laser for imaging

Achievements/Observations

• Collected data for 3 to 4 hours with different samples
• Data collection at lower repetiton rate (113 kHz) with less number of pulses
• Data to characterize the divergence of ASE collected

This day we had lots of issues.

• Nightshift noticed that the mirror 2 feedback was not running anymore since about 22hrs; PBLM2 cam was unknown; powercycling recovered the camera, feedback operational again.
• Continued shooting until ~9:00
• At ~9:30 the whole Karabo, online cluster were dead. No control possible anymore. Whole SASE2 was affected.
• In the meantime, BKR called us, EPS is triggered and bunch number went to zero. However, we didn't (couldn't) change anything due to the Karabo issue. It may be the side-effect of Karabo-issue.
• Karabo slowly came back at ~15:15
• DOC asked us to take test DAQ. JF4 control is stuck at INIT state and cannot take DAQ. DA08 went to error. HED Playground server cannot be restarted.... Need to solve those issues one by one.
• The remaining shift we mostly spent in restarting servers, motors, reloading configurations
• We could not start Jungfrau 4 - at some point the controller was started and has hung in INIT state for the last few hours. It doesn't respond to shutdown commands to initialise it correctly in order. We called DOC, they could restart it.

X-ray delivery

• 1-165 pulses, 1.1 MHz - 28.2 kHz, upto 350  uJ @ 50 pC

Optical laser delivery

• ns laser for imaging

Achievements/Observations

• Collected data for 3 to 4 hours with different samples
• Data collection at lower repetiton rate (113 kHz) with less number of pulses

8.2 keV, 1-2 bunches, 600uJ

23.3.

• did timing runs and optimized the beamline alignment
• Karabo was working very slow
• continued with sample alignment
• performed several xfel+laser shots
• opened the chamber and replaced samples

24.3.

• aligned xfel and Relax to TCC
• sample alignment
• taking shots

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.

the pulse energy in XTD10 is lowered by ~30% when SASE1 changes photon energy, compare att. 1 and 2.

In addition, the intra-train pulse energy stability gets much lower. Potentially, there is an impact on the pointing as well, which is critical for the pump-probe experiment.

X-ray delivery

• 1-165 pulses, 1.1 MHz - 28.2 kHz, upto 400  uJ @ 50 pC

Optical laser delivery

• ns laser for imaging

Achievements/Observations

• Optimized sample setup for data collection
• Calibrated photodiode @ 8keV.
  • ADC signal was saturated with amplified photodiode signal.
  • Removed the amplifier and calibrated photodiode again.
  • ASE signal is visible without the amplifier
• Optimized ASE signal by optimizing the focus and target position in focus
• Checking and optiming the focus everytime chaning the sample disk seems to improve the signal
• Collected data at 8 keV and 9 keV for about 1-2 hours

After SASE1 HIREX GOTTHARD reconfiguration, we now get a single pulse per frame. This was verified by comparing data from HIREX recorded with 564 kHz and 1.13 MHz X-ray repetition rates. Both intensity and number of peaks is comparable for the two repetition rates.

Update for elog 99:

Now Gotthard timing is changed to new setting for 0.5 MHz.

attached screenshot with gothard timing setting

Machine changed from 0.5 MHz to 1.1MHz new screenshot attached2

When using 1.13 MHz X-ray repetition rate, SASE1 HIREX is capturing two pulses in a single frame giving the impression that there are more peaks within the spectrum than there are in reality.

This was verified by recording data with one and  two pulses per train, which are shown in attachment.

The spectral integral/intensity in GOTTHARD frame 6, the first with data, is twice larger with two pulses compared to one pulse per train (attachments 1 and 2).

The number of peaks is consistently higher with two pulses compared to one pulse (attachment 3).

22 Mar 2023, 23:30 Handover from late shift

Tasks for the night:

• source point measurement
• Sample alignment
• timing

23 Mar 2023, 00:39 Source point measurement with CRL1#2,6  Att1,2,3 Meansurements taken on YAG and attenuated beam

• source point: -13.9m
• divergence  : 3.38urad

23 Mar 2023, 02:39 birect BS out, specular in (cf. confluence); CRL4b out, 4a in (at rough focus ? (pos~70mm)); OPT ATT = 1.68e-7;
moved the sample upstream along the target surface (along 359.5deg) to see the downstream edge, brougth ILM and flatfield to fine tune downstream edge to TCC, see sharp edge on ILM and half FEL cut on JF (see attachment5), with IC1 light on two edges (front and backside) are destingushable; target saved to slot slot 26

23 Mar 2023, 03:06 moving the sample edge in hight; on the ILM we see it stays in the focal plane but moves sideways consistently with the JF were the beam gets less and less cut; tried to adjust the angle HEX V (should be around the axis along the FSSS frame) but this seems to be too tricky and time consuming because of the missing pivot point close to TCC. for this reason we can only go in small steps to not bump anything and losing the FOV off the ILM; since every sample will slightly different mounted a better approach might be to compensate the lateral shift in the imaging plane of the ILM by moving along this plane (135deg); for 23mm hight travel ~155um shift along 135deg is needed (after that we had to refocus the target edge by ~20um)

23 Mar 2023, 04:05 we decided now to switch to spatial overlap and timing. The FSI seems to be out of focus. Thats why we go back to a pin and center it to the current FEL beam position and ILM and will adjust the FSI if neccessary

• unfortunately nobody corrected the relay imaging path and/or the filter/beam block stage for the ILM !!
• fine tuned the wire alignment - image quality is very bad on FSI. Not really great on the ILM ( I guess we are clipping in the objective and relay lenses  (Att6 and 7). Seeing now the relative sharp image in the pin, it raises the question why the samples on the image (Att5) on the FSI are blurry.
• could not find t0 within a few ps; thus removed CRL4a, changed from JF (detb_x=820) to OP (detb_x=1151.1), 100% FEL transmission and from OCX to RF lock found back t0 in IC1 (~25ps off from yesterday)
• rechecked PAM spatial for all YAGs, with YAG emission on the camera we went to YAG 100um cross and refocus the objective
• went back to optical lock

During the night we worked on the temporal overlap between Relax laser and XFEL.

In the morning we noticed that the beam jitter is quite large (in and out of the aperture of the CRL4 lenses). There seems to be a correlation with the HED popin. We adjusted the TCC with x-ray and laser. Performed transmission scans.

We managed to see the direct beam on JF. Continued with sample alignment (grazing-incidence) and also aligned the beamblocks to block the direkt and the reflected beam.

During the night we worked on the temporal overlap between Relax laser and XFEL.

In the morning we noticed that the beam jitter is quite large (in and out of the aperture of the CRL4 lenses). There seems to be a correlation with the HED popin. We adjusted the TCC with x-ray and laser. Performed transmission scans.

We managed to see the direct beam on JF. Continued with sample alignment (grazing-incidence) and also aligned the beamblocks to block the direkt and the reflected beam.

X-ray delivery

• 9 keV 1 to 165 pulses ~ 300 mj per pulse - stable delivery during the day

Optical laser delivery

• ns lasers for illumination only

Achievements/Observations

• Focus alignment
• found illumination / shield (100 micron) conditions to optimise background on detector
• observed that the flourecence signal on the diode was very low and this appears corelated with drift in the focus - after focus optimisation signal was again visible
• several runs collected with varying attenuation with the aim to try to corelate flourecence signal on diode with beam intensity

Issues

• Too high background from sample at full transmission required exchange of copper shield form 50 to 100 microns
• disc detaching from motor spindle (twice) - first time disc blocked gate valve, second bolt and washer are in the gate valve mechanisme space
• in both cases detector had to be warmed to allow venting.

22 Mar 2023, 17:08 started the log, the aim for the shift is the alignment of the sample and source point measurement. In addition to that, we also plan to check the Greateyes camera.

22 Mar 2023, 17:53 continuing the sample alignment

22 Mar 2023, 17:54 SAMP_AY is the clockwise direction looking from the top. Positive is towards the smaller incident angles.

22 Mar 2023, 17:57 By moving negative in the coordinated move we brought the sample towards the sliding door when the direction is 90°.

0deg_-alignment-FS.png shows blocking the x-ray beam with the sample.

22 Mar 2023, 18:13 We moved the target paralell to the XFEL beam so that we can either see the direct beam or we block the beam with the target. The next step is to block half of the beam with the target.

direct-beam-0deg.png shows the beam passing by the sample.

22 Mar 2023, 18:39 New zero position is found as on the screenshot New_zero_position_2023-03-22_18-39-16.png 

22 Mar 2023, 19:31 A clear Specular reflection is seen (c.f. Specular_and_reflected_beam_2023-03-22_19-22-19). We now do the angle per px calibration.

22 Mar 2023, 19:35 Specular reflection moves by 41 px for 0.02 deg rotation of the Samp_AY stage. Hence, 20px/0.01deg = 0.00049deg/px

22 Mar 2023, 19:37 We move by 113p = 0.055 deg on Samp_Ay to see the direct beam w.r.t the original sample position. We now move Coordinated motion.

22 Mar 2023, 19:43 Sample aligned parallel to the FEL beam - screenhot attached

22 Mar 2023, 19:48 Sample aligned to an AOI of 0.5 degrees. Screenshot attached. Remember the 2theta shift in the beam angle when the sample stage is rotated by theta. (c,f, AoI_0p25deg_2023-03-22_19-48-29.png - note the angle in file name corresponds to SampAy). Aligned position of the sample is FS_nearbottom_aligned_0.5deg_22032023. This position should be close to the edge at the bottom part of the sample.

22 Mar 2023, 20:54 Direct and Specular beamstops were aligned roughly with ALAS with the IC1 open by CB. We noticed that the breadboard of the specular beamstop motor is not fixed. We now check if this position is fine with the FEL beam without IC1 being pumped. CRL4a shall be driven inside to align this better from the control room.\

22 Mar 2023, 21:52 Direct beam stop was aligned with FEL beam. Specular beamstop was aligned horizontally. Specular vertical axis is only roughly centered.

22 Mar 2023, 22:25 Adjusted c-slits since they were clipping the beam before. p-slits are aligned as well.

22 Mar 2023, 22:48 Now we try to see something on the Greateyes. We bring in Relax alignment laser. Removed filters in IC1, free position in spectrometer. Switched off sensor power. Please insert the filters again before any laser shots!

22 Mar 2023, 23:10 We see something, but not clear what it is. Att. #7

Got the beam, aligned it up to the TCC, mirrors in 3 mrad configuration, checked positions for the CRLs. Energy up to 500 uJ at 8.2 keV, 2 bunches. 
Feedback M2 PBLM-2 camera was UNKNOWN. Power cycle (just switch off >> on) solved the issue. Also, the screen was extracted. Insert the screen. However, the count is too low (30 counts) to make the feedback running. We found that the trigger timing for the PBLM-2 camera was off by 20 msec with unknow reason. Then we had >~200 counts. 
The beam jitter on Zyla was quite large (~1-2x beam width).

Installed and aligned CRL4a and b. Then we pumped IC1. We realized that the M2 feedback went off two times, this needs to be checked from time to time. Otherwise no big issues, beam is mostly fine, energy is also fine.

Staff: JB, PV, TS, RL, RdW, JK, AR

X-ray delivery

• 1-165 pulses, 1.1 MHz, upto 400  uJ @ 50 pC

Optical laser delivery

• ns laser for imaging

Achievements/Observations

• NKB focus optimization
• Beam alignment until IBS
• Photodiode alignment
• Alignment of fixed target in the beam
• Tests with fixed target motion in vacuum
• Collected few runs with low transmission at 8 keV and 9 keV

After setting timing witht he diode, we look at the PAM spectrometer and scan the laser timing a bit.  We found a clear change in the spectrum - at >t0, the spectrum was very attenuated and at t<t0, the spectrum was larger.  This persisted for many 10s of ps (very unexpected behaviour).

In attachment are the LA3 timing scene, the SQS delay stage, the BAM, and the spectrometer signal from Metro at t0. att. 1 - 4.  The averaged ratio shows the cut the best.  Unfortunately we do not have references on that, so we will ask Sergey or Bjoern to do it tomorrow.

We found that the intra-train timing feedbacks of the accelerator are off. We ask BKR to fix it, which took a while. Aparently, we have to communicate the need of the timing feedbacks (and BAM) more clearly.

Standard deviation along train is now 18 fs with feedbacks on, see att 5. Was around 100 fs without the feedback!

We take a run and manually move the PAM delay stage so we have a timing calibration for PAM.

run 32: Rubbish because DA03 got stuck.
run 33: scanning PAM delay stage manually. device: SQS_AQS_LAS/MOTOR/WAVEPL_LMD2_1030. Typically taking 5um steps.

Went to the PAM delay stage position shown in att. 6, and had the PAM signal shown in att. 7

Activities:

• Measured tr-RIXS spectra on user sample in silane solvent

Problems:

• Sometimes the PPL shutter cannot be opened from the control room after searching the hutch.

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