[Aso, Takano, Washimi, Ushiba (remote), Komori (remote)]

We searched for the resonant frequency of the EX drumhead mode to try beacon ASC to reproduce the O4a situation and improve the OMC trans spectrum.
At previous Q-measurements, we used a channel of K1:MIR-AS_PDA1_RF17_I(Q)_OUT.
However, we cannot see the excited peak in this channnel, so we measured more sensitive channle, K1:ASC-OMC_REFL_QPDA1_I(Q)1_ERR.

We succeeded in finding the resonant frequency and estimated the Q-value from the line width.
These results are summarized in the list with those of previous measurements at different mirror temperatures.
The smaller resonant frequency is reasonable due to smaller Young's modulus, and the Q-value is even smaller.

The result of the beacon trial will be posted later.