Schedule: finalise installation of NEN and NWN, rearange all cablings

15 June 2026 : Start installation around 15:00 utc

• Position adjustements for NEN setup:
  • Adjust zero positions with jig for North East setup in /virgoData/VirgoOnline/SNEB_dbox_rack.cfg:

    	NEF lateral	NEF Vertical	NEM Axial	NEM Vertical	NEN Lateral	NEN Vertical
    Old values	-7.661	-7.03	7.435	8.225	7.954	7.306
    New values	-7.1195	-6.7015	7.1135	6.607	6.651	7.06

  • Mean of sensors values now 0 within 1 micron precision.
  • Remove jigs and align setup to better than 0.05 mm (see NEB_EastSetupAlignment histograms)
• Position adjustements for NWN setup:
  • Adjust zero with jigs in /virgoData/VirgoOnline/SNEB_dbox_rack.cfg :

    	NWF lateral	NWF Vertical	NWM Axial	NWM Vertical	NWN Lateral	NWN Vertical
    Old values	7.05	-7.12	-7.753	6.7530	-8.035	7.063
    New values	6.777	-6.9343	-6.9823	6.7602	-6.9060	6.7322

    Means of sensors values below 1 micron now

  • Remove jigs and align setup to better than 0.05 mm (see NEB_WestSetupAlignment histogram)

• Position adjustements for NSN setup:
  • Adjust zero with jigs in /virgoData/VirgoOnline/SNEB_dbox_rack.cfg:

    	NSF Lateral	NSF Vertical	NSM Axial	NSM Vertical	NSN Lateral	NSN Vertical
    Old values	-7.444	7.619	-7.361	-7.691	7.004	-7.764
    New values	-7.0234	7.2171	-7.0236	-7.3403	6.4019	-7.3625

    Mean sensor values below 3 micron now

  • Night pause...Continue on June 16th (7:00 utc)
  • Remove jigs and align setup to better than 0.05 mm (see NEB_SouthSetupAlignment histogram)

At the end of the intervention we have :

Box 2021-08 (R4-32) on NSN with LED "away" from mirror

Box 2024-12 (R4-12) on NEN with LED "away" from mirror (and generating loop attached)

Box 2021-04 (R4-30) on NNN with LED "close" to mirror

Box 2024-10 (R4-10) on NWN with LED "away" fro mirror. It produces more accoustic noise than the others

The rotor cables for NWN have been installed

All rotors have been tested during few minutes at 50Hz.The difference in acoustic noise between the NNN and the others was less noticeable than at the nominal frequency.

All microphones gain have been set to 40dB (East and West setup were at 60dB. South was at 40 dB... We don't remember for North).

All temperature sensor gains have been adjusted to follow the new cabling on the DAQ boxes.

NB: During the NCal  power supply reshuffling, we touched the ring heater power supply connector and the power supply switched off for a short time (on 15 June 15:30 UTC). Ring heater experts will come to check.