We cross-checked the timing. Laser pulse is detected at bins 136 (PD-North) and 171 (PD-south), respectively. Therefore, the laser puls is in the electron cooler at 153.5. The revolution period corresponds to 3e8Hz / 1.54315MHz = 194. 
The ion bunch must travel 2.5m more than the half of the circumference (108.3m). Taking this into account, the ion bunch must be detected (0.5 + 2.5 / 108.3) * 194 = 101.5 bins later (meaning less) than 153.5.
Finally, we are happy that the timing is still perfect, since the ion bunch arrives at 52. 

We checked the timing (before the start of the measurement cycle documented below).
Timing and measurement window are attached.

current settings of PMT voltages and thresholds at the CAEN CFD:

PMT South   [HV ch2: 2700V]  [CFD ch0: 8]

PMT Middle  [HV ch1: 2850V]  [CFD ch1: 8]

PMT Nord    [HV ch3: 2850V]  [CFD ch2: 9]

Cobra's FCU was recalibrated. Table saved as FCU_547-554_RS_2024-06-25.fcu.

In the SetParameters.C file is a parameter called fPar->piPhaseOffset. It was shifted from 100 to 50 in order to see ion bunches in the pmt signal and laser pulses in the photodiode signal during the same revolution in the TDC spectrum. Note that this parameter must be taken 
into account when setting the window conditions of the arrival time in the SetConditions.C file. 

We tested the PMTs again, this time with an UV LED that is mounted at a window close to the XUV detector.
PMT south showed a very clear increase in count rate from about 1 to 50 Hz.
PMT mid also showed a small increase by a few Hz.
For PMT north there was no great change between LED off and on, but we think that the count rate also very slightly increased. Note, that PMT north is also the furthest away from the LED.

Also we saw a difference between single- and multi-photon events at PMT south.

We exchanged the old BBO of the Cobra's FCU with a new one. The output power of the Cobra was around 120mJ. In the end, we achieved a UV power of about 21mJ. In addition, we optimized the fiber-coupling to the wavemeter.