Virgo Logbook

AdV-PAY (NI and WI Payloads)

majorana, ruggi - 22:21 Thursday 30 July 2026 (69480)

Magnet ! @ WI

At 20:30 I was informed by Paolo, who had restarted the prealignment works, that one actuator on the WI Mirror did not respond. Probably the magnet detached. Quite strange as apparently no significant shakes occurred through the suspension system. Just to be definitely sue of what occurred, an electrical check on the flange, to see if the coil is connected is worthwhile. We do not know when it happened because it was the firs time these actuators we used (to crosscheck and tune the driving)

Comments to this report:

mwas - 8:01 Friday 31 July 2026 (69481)

The up-left coil looking from the rear side has an issue with the shielding of its cable https://logbook.virgo-gw.eu/virgo/?r=69386

Is that the same coil-magnet pair which is not responding to DAC actuation? Electrical checks should be done as a priority in any case, but if the up-left coil-magnet pair is the issue, then it makes it more likely that this is an electrical problem.

majorana, gherardini - 9:46 Friday 31 July 2026 (69485)

On Monday 3/8 a further check through the flange will be done (Gherardini), in the remote possibility the issue is there. I write "remote" because the electrical check was regularly
done as the last one before leaving the chamber.

majorana - 9:48 Friday 31 July 2026 (69486)

Yes, a xcheck will be done on Monday.

ruggi - 10:24 Friday 31 July 2026 (69488)

Plots showing the result of WI MIR actuation cheks are attached. If a voltage is generated by UL DAC (seen by the monitor inside the board), no effect is visible on the mirror orientation (fig 1). If the same is done with one of the other DACs, the rotation is well visible (fig 2).

Images attached to this comment

Gherardini, Pinto - 11:08 Monday 03 August 2026 (69494)

This morning we did an electrical check of the WI mirror coils and their cable (S): from the tower flange to the in-vacuum device everything is fine, we read the right resistance value for all the coils without any shortcuts to the ground; then also checked that the voltage provided by the coil driver arrive to the mil-32 connector and it works correctly.