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MIF (General)

tomotada.akutsu - 19:30 Thursday 27 June 2024 (30142)

Final optical alignment with in-vac TMSY optics before closing it

Ushiba, Akutsu with Michimura, Haoyu, Shalika, Kawaguchi

Summary

Tweaked in-vac steering mirrors in the TMSY chamber (EYT chamber) to bring Gr and IR beams to the in-air periscope. Also we checked the inside of the chamber and found no clipping tendency both for IR and Gr.

Green

We did not find any severe off-centering of Gr beams in the chamber; good centering seemed kept (Fig. 1). On the other hand, the green beam spot on the upper steering mirror of the Gr periscope on the in-air optical table was clipped, so we tweaked the final steering mirror (for Gr) in the chamber to improve the alignment. Now the Gr beam spot is around the center of the upper mirror of the Gr periscope.

IR

We did not find any severe off-centering of IR beams in the chamber. good centering seemed kept. The IR beam spot on the upper steering mirror on the IR periscope was not severely off-centered (about 5 mm or so) but, we determined to adjust this with the final IR in-vac steering mirror. Now the IR beam spot is around the center of the upper mirror of the IR periscope.

Hopefully further optical alignment in the downstream will be reported by Michimura-kun et al.

Images attached to this report

Comments to this report:

takafumi.ushiba - 21:06 Thursday 27 June 2024 (30145)

Figure 1 shows the beam spot of GRY on the upper mirror of the periscope.
Obviously the beam was clipped (the beam was hit on -X +Z direction on the mirror holder).

Figure 2 shows the beam spot on the same mirror after adjusting the last steering mirror for GRY inside the TMSY vacuum chamber.
The beam spot seems almost center.

Images attached to this comment

Haoyu Wang - 23:32 Thursday 27 June 2024 (30147)

Michimura, Shalika, Kawaguchi, Haoyu

We aligned the beam at the TMSY table after changing the beam height on the upper mirror of the IR periscope. The beam height looks good at RLNS1 and RLNS2. Both GR and IR optics and detectors are centered, including GR PD, GR QPD1, GRQPD2, IR PD, IR QPD1, IR QPD2, IR S-pol PD and IR P-pol PD.

We didn't check whether beam dumps are properly dumping or not this time. It may be good to check this sometime when the Yarm lock and alignment is improved.