KAGRA MIR (Polarization)
MarcEisenmann - 16:37, Thursday 10 August 2023 (3311)
spare ETMY measurement started

[Aso, Marc, Michael, Rishabh]

We installed spare ETMY with ears up (ie reversed top/down with respect to KAGRA installation) on the translation stage.

It helped a lot to remove the front top right metal support looking from the laser side for the installation.

After small realignment of the 2 photodetectors I checked the mirror center by trying to find the position where the signals drop to 0 (ie edge of the mirror).

X_center = 393.5 mm and Y_center = 155.5 mm.

Then I started measurement with Spol at the input (HWP = 351.2 deg) with maximum AC and DC dynamic range (1V) to take map over 70 mm radius with 1 mm step.

I'll keep these settings during holydays to avoid saturation.

Comments related to this report
MarcEisenmann - 09:33, Thursday 24 August 2023 (3314)

The measurement seems to go fine and is mostly finished.

However, because of the new failure of air conditioning the temperature and humidity increased quite a lot in TAMA.

It's about 30deg in main building and quite more inside clean room.

just for safety I turned off PCI laser.