Friday we performed some tapping test on almost all the mirrors mount located on the optical path from the output of the Laser bench and SIB1.
The resonances and associated GPS of the tapping tests are listed below :
| Mount | GPS start | GPS Stop | Freq / DOF |
| M1 | 1184049487 | 1184049500 | 786Hz (hor) |
| M2 | 1184049531 | 1184049541 | 538Hz (ver) 529Hz (hor) |
| M3 | 1184049551 | 1184049563 | weak |
| M4 | 1184049582 | 1184049596 | 350Hz(ver) |
| M5 | 1184049631 | 1184049644 | 410Hz |
| T2 | 1184049754 | 1184049764 | 547Hz |
| T3 | 1184049774 | 1184049781 | 491Hz |
| T4 | 1184049810 | 1184049818 | 441Hz 1019Hz |
| M6 | 1184049895 | 1184049903 | 201Hz 265Hz |
| M7 | 1184049931 | 1184049939 | 821Hz |
| M8 Before | 1184049968 | 1184049975 | 226Hz 257Hz |
| M8 after | 1184055900 | 1184055916 | 403Hz |
The spectrum of the above listed injections are shown on the attached plots (from Figure 1 to 10, blue curve = exited purple curve = quite).
The mount of M8 has been changed, from Picture 11, to hardner the resonance. The comparison of the two noise injection on M8 is visible in Figure 12 (purple = old mount, blue = new mount).
The effect on the sensitivity is visible in figure 13 as a small improvement at 220Hz. It is worth to be noted that no worsening of the sensitivity is visible at the new resonant frequency @403Hz.
