our pp laser experienced timing jumps by 18 ns today. this happened for the first time at ~7:30 in the morning without us noticing and a couple of more times during the morning. we realized it at 15:30 due to the fact that the signal on our pulse arrival monitor (X-ray/laser cross correlator downstream of the experiment) disappeared. we spent some time to investigate it, until we also see this jump in two different photodiodes different triggers (oscilloscope and digitizer) so it was clear that it is indeed the laser timing jumping. we also see the laser spectrum and intensity change for the trains that are offset in timing.

we called laser OCD at ~16:30. they have been trying to fix the problem by readjusting the instability zone multiple times and by adjusting the pockels cell, but this did not change the timing jumps. at 21:30 they concluded that there was nothing more they could do tonight and a meeting should happen in the morning to discuss how one can proceed.

effectively, this means that we lost the entire late and night shifts today for the pump-probe beamtime and have some data of questionable quality from the early shift as well.