The new ITMx monolithic welding has been successfully completed and was left suspended overnight last night. The majority of the modal measurements have also been completed today, with the exception of the violin modes, which are proving to be trickier to measure than in previous suspensions. We will continue with these measurements tomorrow with some different equipment. Stay tuned for subsequent posts with IAS and modal measurement numbers.
Modal frequencies of the test mass (ITMX) with the PUM nominally locked are: ITMX value resolution Pendulum 0.649 0.002 Pitch 1.1153 0.002 Yaw 1.0928 0.002 Bounce 6.74 0.016 Roll 9.195 0.016 Violin modes fibre serial number BR 499.9 0.06 S1400155 BL 501.2 0.06 S1400156 FR 500.8 0.06 S1400138 FL 502.2 0.06 S1400153 [just as a note to self as much as anything - remember to use the Uniform window on the spectrum analyser for the violin modes when using the chirped sweep output]Forgot to post this last week. Final alignment numbers from the ITMx welding (all directions/rotations reported from the view of the IAS equipment, i.e. looking at the HR face of the ITMx):