Reports until 12:38, Wednesday 27 September 2017
H1 IOO
cheryl.vorvick@LIGO.ORG - posted 12:38, Wednesday 27 September 2017 (38808)
Tower bolts on IM1 torqued

I torqued the bolts on the IM1 tower, and found many that were loose enough that I could easily get them to travel one quarter of a turn before they tightened up.

The bolts were 1/4-20's on the sides of the towers, and 8-32's on the sides, back, and top of the towers, and some smaller screws that hold the EQ stop brackets.

The 8-32 screws on the top of the tower that moved by one quarter of a turn, included every bolt that is associated with the blade spring attachments and alignment.

The LENGTH signal changed by about -25, PITCH changed by about -300urad, and YAW didn't change.

In my initial inspection, before torquing bolts, I saw sufficient space between all EQ stops and the optic, and between the upper and lower magnet assemblies, so no evidence of a direct mechanical interference.

Plot of the OSEM changes is attached.

Images attached to this report