KAGRA MIR (General)
MarcEisenmann - 13:00, Wednesday 08 December 2021 (2749)
spare ETMY birefringence measurement started

Abe-san, Marc, Matteo

Yesterday we installed the spare ETMY on the translation stage.

With eye inspection, we could see dusts on both surfaces that should be cleaned before the absorption measurement.

Using the probe laser we found X_center = 397.5 and Y_center = 111.635.

The Z position is 80 mm which corresponds to beam waists about 1 cm in front of the mirror center.

After alignment and calibration, we took a first measurement with 70 mm radius with s polarization.

A next measurement with polarization angle about 30 deg is on-going