Giles report from yesterday's work:
(Travis, Mark, Jason, Doug, Giles)
After leaving the PUM hanging overnight there was no further development of the crack. We then proceeded to re-lock the PUM and hang the ETM to perform modal measurements. Using the autocollimator we measured the longitudinal, pitch and yaw modes. We then setup and optical lever to measure the transverse, bounce and roll modes. Finally we measured the 4 fundamental violin modes. The modal data gathered was:
Longitudinal 0.656 Hz
Pitch 1.09 Hz
Yaw 1.09 Hz
Transverse 0.656 Hz
Bounce 6.75 Hz (this will be sqrt(2) higher when the PUM is free)
Roll 9.6 Hz (this will be sqrt(2) higher when the PUM is free)
FR 505 Hz
FL 506.5 Hz
BR 506.5 Hz
BL 505 Hz
We finally installed the fibre guards and covered the entire lower stage.
Serial Numbers of fibers on the suspension now:
FL S1300183
FR S1300191
BL S1300190
BR S1300193
S1300186 was trashed during the welding as it was installed and then cut out as noted above.
Correction: BR is actually S1300173.