There was a clipping at the edge of reflecting mirror of IFI pick off, and the clipped beam was seen on a sensor card.

Today,I shifted the position of reflecting mirror to IMMT2 direction and the clipping was perfectly gone.

At the same time, the aluminum shim which was located under the mount plate of the reflecting mirror to align pitch to the center of view port was replaced to SUS shim plates.

I used 0.2mm x 3 shim maximumly but the pitch angle was almost the same as when I used 2 shims. Shims are not so effective since SUS shim is stiffer than almunum shim. This is because when the screw is tightened the base plate of mount will be close to parallel. After all, I decided to used 2 shims and the beam position is 2cm above from the center of viewport.

One more thing, last time Yano-san and I worked on setting the reflecting mirror, there was a doubt our work might introduce some large shift of optical table. When I loosened the screw for the first time today, the screw was not tightened hard at all, or rather soft. It means that Yano-san didi not tighten the screw so hard last time. I looked at the IMMT1 QPDs during today's work, and I did not see any significant shift of the optical table. I guess optial table is so firm, so it means that something happened last time and it might introduce kicking the optical table.