Results:
NEB is ok. The measured coupling is the same measured in February: 1.4E-21 (was 1.8E-21 in Feb.):
Figure 1: show injections at NEB (tried two amplitudes)
Figure 2: shows fit of injection #1
Figure 3: fit of injection #2
WEB was found a factor 2 worst than in February: we initially measured a coupling of 4E-20 (was 1.6E-20 in February). This might be consequence of the installation of the new cover, but as well might be due to time drifts (we already observed in the past that coupling changes from time to time possibly due to alignment condition). Benjamin and Julien did not see any evident problem (scattering sources) but they managed to improve a bit the situation re-aligning beams on bench. The last measurement gave a coupling of 1.8E-20, basically same as in February:
Figure 4: shows injections at WEB (before and after)
Figure 5: fit of injection before
Figure 6: fit of injection after
Figure 7: projections of NEB and WEB noise
Concerning WEB the message seems to be: a factor 2 or so increase of diffused light noise might be possible in the long term, which could become noticeable at 20-30Hz , should keep an eye on.
