At 5:20 UTC ITF in Calibration mode to perform the scheduled magnetic injections.
At 7:00 UTC ITF in Maintenance mode, here a list of the activities communicated to the control room:
- vacuum activities and cryotrap refill;
- work on suspension by Paolo and Valerio;
- work on the ISYS by Gabriel and Camilla;
- spare electronics installation in DAQ room by Flavio;
At 10:00 UTC all the activities were concluded.
At 10:05 UTC ITF in Troubleshooting because the ISYS was unstable; Gabriel and Camilla were able to fix the problem. They discovered that during the maintenance some ISYS electronics was accidentally switched off; this had as a consequence that the ITF was not lockable any more (for more details see dedicated entry).
At 11:51 UTC ITF locked with squeezing injected and PRCL->SSFS subtraction disabled.
At 12:02 UTC Troubleshooting mode stopped.
At 12:12 UTC ITF in Science mode with a bad sensitivity; Horizon around 43 Mpc.
At 12:44 UTC ITF in Commissioning mode for Squeezing activities.
At 12:54 UTC I enabled the PRCL->SSFS subtraction and I reloaded ITF_LOCK.py with the lines uncommented.
Vacuum
TankLN2 -> VAC..WE1_LN2_BAR is red after the maintenance activities; it should turn into green in the next hours.
Infrastructures
UTA DET in portatat nominale from 6:39 UTC to 9:46 UTC for work in DET LAB by Romain.
TCS
standard check and refill of the TCS chillers.
Downtime events
from 10:05 UTC to 12:12 UTC because some ISYS electronics was accidentally switched off in the maintenance break; see next dedicated entry.
At GPS = 1239456611 we performed a CC phase scan to optimize the squeezing level (length = 780s). The plot of the phase scan is shown in the attached Figure. The distance between the minimum of the magnitude and the best squeezing level is -0.61 rad. With the scan we found -2.8 dB of squeezing and 5.3 dB of anti-squeezing.
The CC phase that maximize the squeezing is 0.21 rad and the slow CC loop set point is 0.6e-3 V.
Before the tuning the optimal squeezing phase was 0.54 rad and the slow CC loop set point was 0.15e-3 V. Thus before the optimization -2.2dB of squeezing were injected.
