With Hirata-san, Ikeda-san and Washimi-san.

Summary: it seems the IM and IRM are touching each other.

See pictures in album PR3 Remedying Work.

In the clean room we inspected the OSEM flags and their positions were as indicated in this diagram in the notebook:

• H1, V1, V2 and V3 indicate there is large amount of positive pitch.
• H2 indicates there is a lot of negative yaw.
• We did not inspect H3 because it's hard to see without opnening the +Y door.

The pitch effect seemed larger so we decided to try to remove it first.

• Assuming the origin of the problem is the pitch of the BF, we added temporary ballast mass on the +X side of the BF top.
• This corrected the pitch in an amount large enough to make the flag seem free from touching, however, the IRM also moved in towards -X such that the OSEM was rendered out of range.
• We removed the ballast mass and saw that the H1 readout is reasonable, actually, relatively close to zero. This suggests the problem might not be the amount of pitch of the BF.

We should aim fix IM-Yyaw first. As reported in entry 16043, before entering ther mine we had set IM-Y close to zero using the picomotor, however, while removing the cloth covers from the chamber duct openings and turning the Koach filters on, IM-Y was disturbed too much. Namely, it went from around zero to about -500 urad. See the attached picture.

Tomorrow we will open the side doors of the chamber and carefully inspect H2 and H3.