Virgo Logbook

Virgo Runs (O3)

Nenci - 15:03 Sunday 08 September 2019 (46861)

Operator Report - Morning shift

The ITF unlocked at 7:14 UTC therefore I contacted the ISC expert (Valerio at 7:15 UTC) in order check / adjust the MC_F0 position (pending action). V. Boschi restored the standard working condition but in meanwhile we had problems with the MC power transmission that was too low, therefore I contacted the injection expert (Camilla at 7:40 UTC) in order to investigate the problem. At about 9:00 UTC I restarted the lock acquisition and, after a few attempts, I engaged the Science Mode (9:59 UTC) but unfortunatly the ITF unlocked at 10:43 UTC seems due to a fast unlock (picture n1 attached). At 11:06 UTC I achieved again the Science Mode but the ITF unlocked after a few minutes, it seems again due to an IMC fast unlock (picture n2 attached). After that I collected several unlock attempts during the acquisition mainly due to the bad weather condition (wind and sea activities) that are worsening. Finally Science Mode at 12:46 UTC despite the weather condition.

Enviroment / windactivity

10:04 UTC - GIPC in "wind cfg", I activated the procedure for "moderate wind", from the PR Gains Client I put the SW_SW Gain value from 1 to 0.

Oncall events

ISYS
(08-09-2019 07:30 - 08-09-2019 08:30) From remote
Status: Ended
Description: MC power transmission that was too low

SUSP
(08-09-2019 07:15 - 08-09-2019 07:45) From remote
Status: Ended
Description: Check and restore the MC_F0 value

Images attached to this report

Comments to this report:

derossi - 10:07 Monday 09 September 2019 (46865)

After end mirror of the IMC had been moved, the IMC cavity was slightly misaligned and the transmitted power went below the threshold for closing the Aa.
By manually bringing the injection bench in the former position the usual transmitted power was recovered and it was enough to close again the IMC automatic alignment.

gosselin - 10:57 Monday 09 September 2019 (46867)

The two unlocks metionned in the entry 10h43:03 and 11h10:02 are not fast unlocks but due to the BPC.
The corrections went to 0 and the beam drifted till the unlock.

minazzoli arnaud cohen cleva - 16:32 Monday 09 September 2019 (46871)

Whereas the unlock is not a fast unlock, there has been a burst of fast EOM glitches on Sunday (September 8th) between 16:55:25 and 16:56:35, when the first fast EOM glitches since August 9th were trigered. See fig. 1. The first among of few glitches is displayed in fig. 2, with an "unzoom" in fig. 3.

Those glitches are not related to an unlock.

The fact that they appear right after the ITF comes back in science mode (c.f. 46862), and not before, is due to the fact that our code only tracks the glitches when the ITF is in science mode.

Images attached to this comment