(Log on 21st)
[Takahashi, Hirata]
We implemented the laser displacement sensors to measure the vibration of the suspended breadboard (BB) in SR2 and PR2. The laser sensor IL-600 was set on the viewport for the GigE camera and aligned to the top of the baffle on the BB in SR2. The other sensor LK-500 was set on the viewport for the GigE camera and aligned to the suspension wire for the BB in PR2.
Continued work from klog23317.
[Hirata, Ushiba]
We measured the spectrum of suspended optical table in PR2 and SR2 chamber.
Figure 1 and 2 show the spectra of PR2 and SR2 optical table displacement, respectively (not calibrated).
The peak in fig1 is at 0.42 Hz, which is consistent with the ALS measurement (klog23229) within the bandwidth of the measurement (15.6 mHz).
So, the 0.43 Hz phase noise is coming from the motion os suspended optical table in PR2 chamber.
However, the peak in fig2 is at 0.33 Hz while the peak in YARM ALS is about 0.38.
Since this differrnce is larger than the resolution, it is unlikely that ALS-Y phase noise is coming from the table in SR2 chamber.
More investigation is necessary.
[Takahashi, Mitsuhashi]
We measured the spectra of the suspended breadboards again.
PR2: The peak due to the pendulum mode was observed at 0.43Hz, which is consistent with the last measurement. The microseismic was smaller today, so the peak amplitude was smaller than the last one.
SR2: The SNR of the measurement was not good. The peak at 0.39Hz was larger than the peak at 0.33Hz a little, but it's not clear.
