[TomarUchiyama, YokozaWashimi]

This is the map of tapping/shaking point in PR booth.

Though the strength of shock were not constant, but in our feelng, 

• The bellows and beam ducts MCF chamber are very sencitive (many peaks and bumps in 200-800Hz). But the chamber body and the chamber legs are in sencitive.
• If it becomes far from the MCE chamber, the effect is smaller.
• IMC REFL table, its alminium foil, ISS table are not sensitive.
• shaker injection into the IFO REFL table -> 520Hz bump grows up. 

From these results, the path of acoustic noise in DARM (see http://klog.icrr.u-tokyo.ac.jp/osl/?r=13407) came from

• 280Hz, 360Hz bump (peaks) -> MCF bellows
• 520Hz bump -> REFL table