[Steve / Kiwamu]
An attenuator, consisting of two HWPs and a PBS, has been installed on the PSL table for the MC low power state.
Those items allow us to reduce the amount of the incident power going into the MC.
We haven't decreased the power yet because we still have to measure the arm lengths.
After we finish the measurement we will go to the low power state.
We have adjusted the polarization after the last HWP using another PBS. Now it is S-polarizing beam.
After the installation of the attenuator the beam axis has changed although we were immediately able to lock the MC with TEM00 mode.
I touched two steering mirrors on the PSL table to get the transmitted power of MC higher. At the moment the transmitted power in MC_TRANS is at about 30000 cnts.
The attached picture is the setup of the attenuator on the PSL table.