Virgo Logbook

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AdV-DET (Commissioning)

gouaty, mwas - 17:21 Monday 08 April 2024 (63886)

Change of relay shape for the switch from blended to DC channels, update of B1 blending filters

Following the suggestions made in https://logbook.virgo-gw.eu/virgo/?r=63876, we have proceeded with the following actions:

We now use a sin^2 shaped relay for the transition when we switch from the blended to the DC channels of the B1 PD1 and PD2 photodiodes. The SDB2_Photodiodes vpm process was stopped/started at 10h51 utc for this purpose.
The blending filters of the B1 PD1 and PD2 photodiodes have been updated, using the data collected last night (April 7) in Low Noise 3 at 21h00 utc (2 min). SDB2 photodiodes filters reloaded at 15h12m57-UTC.

Comments to this report:

gouaty - 18:42 Monday 08 April 2024 (63887)

We checked the blending of the B1 photodiodes using the data collected in Low Noise 3 this afternoon, starting from 16h05 utc.

The attached figures shows the obtained spectrum for the blended signals of each photodiode compared to the DC channel and the corresponding transfer functions.

The situation has been improved with the new blending filters, but is not yet perfect in particular for the B1_PD1 photodiode.

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