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.