Yano, Akutsu (remotely Ushiba) Follow up of 20218 and 20224. Continued to 20265.

Abstract

Inspected what had happened in the IFI chamber. We confirmed the STM1 and 2 structures were rigid. We finally tweaked yaw picomotor of STM2 mirrror holder handly so that the beam spot on the IMMT1T QPD got roughly centered. Anyway, I am not sure why this indcident had happened.

Details

We started with inspecting carefully the structural rigidity of the STM1 and STM2 mirror holders and pillars; they were rigid enough. We also inspected the beam clipping on the IMMT1T table. FInally I tweaked carefully STM2 in the yaw direction and Yano-san looked at the beam spot move on the IMMT1T table. Then, I further tweaked the STM2 yaw with monitoring the IMMT1T QPD. After these, we checked the beam spot on IMMT2, PR2, and PR3. On PR2, the IR beam spot is ~ 1cm lower than the center of the target (Fig. 1), and the similar situation was observed on the PR3 target. Anyway the beam passed the PR2 mid-size baffle aperture, so we stopped our work in the morning. The follow up of this story will be done in the afternoon by Matteo and colleagues.

Notes

• By the way, the IFI-CWP1-STM (Miyakawa-san installed in 20218 ) was, to compensate the pitching of the reflected beam from CWP1, set with some folded aluminum foils underneath the mirror holder. This part should be revisited later, maybe (Figs. 2 and 3).
• The ground near the IFI chamber was wet due to spring water..., which was just "stopped" with a dirty paper. Need to be replaced with proper ones... (Fig. 4)