YamaT, Miyo, Uchiyama, Akutsu

Abstract

After 16236, observed that the IMC flash without any additional alignment of IMC mirrors (and IPs in the PSL room). Also checked how the input beam alignment was sensitive to IP PZTs, and learned they were not so much effective.

Details

As in 16225, MCo and MCe have been already "aligned" by referencing oplev zeros, while MCi was not (because I had broken the reference already; see 16126 and so on.) Then, we observed that the transmission from MCo was flashing in several higher order modes and sometimes TEM00. Due to wind from KOACH filters, the MCi and MCo suspensions were disturbed mainly in yaw, and so do the resonance of light.

For the future work, we checked the angular efficiency of the IP PZTs (in the PSL room)to the input beam. So we checked what amount the beam spot on STM1 could be moved by these IP PZTs (Fig. 1; the cross red light lines were from the laser level, while the wider spot at the lfet above of thee cross point was the fluctuating transmission main beam). But we learned they were very insensitive... well, when the PZT actuated one of the IPs in pitch, we could see the transmission mode became higher order mode, so I believe the PZTs would be able to work, but maybe not suitable for the rough initial alignemnt. I need to check the efficiency of the PZTs.

By the way, in 16161, I did not use a laser level but today we used it and confirmed that STM1's height is 210 mm from the top of the IFI optical bench (Fig. 2).