We started playing with the detector pockets of the pleiades arrays at 14:23 01.04.2025.

This might disturb the beam sometimes.

The beam is lost in SIS at 14:35. 

Beam came back at 16:40, we continued playing with pleiades positions until 17:14.

Beam resumed at 16:40. 

Leakage currents were steadily increasing in the PLEIADES detectors so we decided to stop taking data, move both the detectors back and turn off bias.

HKR just called to say a power supply to the SIS18 extraction kicker has failed.
The service person has been called and is expected to take ~1h to arrive and approx. ~2h to carry out the repair.

Starting at around 04:09 we don't see anything on RSAs. RSAs are still triggering and writing files, but only see noise. Lassie indicates beam current in the ESR

We called HKR, they said they will investigate, awaiting response.


last file that contains data: RSA01-2025.04.02.04.09.27.044.tiq_spectrogram.npz
file from which only noise is contained: RSA01-2025.04.02.04.09.31.905.tiq_spectrogram.npz 

At 04:09: drop of beam in the SIS as shown in screenshots.


For a minute there were still good data. Files from:
RSA01-2025.04.02.04.13.44.629.tiq_spectrogram.npz
to:
RSA01-2025.04.02.04.14.47.805.tiq_spectrogram.npz



05:30 update from HKR: There is a problem with the ESR main power supply. We have to wait.

Beam was returned to the ESR at 05:11.

HKR said there had been some problem with one of the dipoles and in order to restore it a power supply had to be reset, which took some time.

05:41 data are back in the RSAs. Files that contain data from:
RSA01-2025.04.02.05.41.14.938.tiq_spectrogram.npz
to:
RSA01-2025.04.02.06.24.01.530.tiq_spectrogram.npz


06:24 data not visible again, only noise.

06:43 data are ack in the RSAs. Files that contain data from:
RSA01-2025.04.02.06.43.43.580.tiq_spectrogram.npz

07:20  we have beam back.

7:29, beam gone again, operators say they need another 5 minutes.

After the beam  was restored at 07:25, we think that the frequency peak in the 244 MHz RSA2 has jumped again (closer to the center). 
Previous to that, during the longer break in the previous night, the peak jumped to higher frequencies.

The SIS kicker has failed again at 08:01.
Since this has happened already few times, the experts from the on-call duty service are now looking at the problem.

The beam is back. But, the experts have found a problem with one of the modules of the SIS kicker magnet. And, currently they have disabled this module. This fixed the problem. However, since the kicker system is not running with full power, it is not clear by how much this can affect the extracted beam intensity for the ESR. Therefore,  the ESR experts have been called and they will look at the injected beam intensity in the ring, in order to know if its still the same as before disabling the module. 
The experts will discuss at the upcoming meeting how to proceed with the damaged module, i.e. when to repair it.
In addition, the FRS started to take the beam now (again) which means that we will be getting less pulses from SIS as compared to the previous night.

Since the FRS started to take the beam again, the ESR gets 1/10 shots from SIS. But, the ESR seems to request about twice more frequently the beam from SIS which means that every second shot in the ESR is empty (it contains the remaining beam from the previous injection). This also applies to the data stored by RSAs because they also (seem to) trigger each time the ESR requests the beam.

beam is back, we started DAQ again. All files created after 15:45 should be good from now on.