At the beginning of this week we proceed some extra checks of local control problems.

First of all we get some transfer functions of some mirrors. Attached to this entry are some strange TF. For example the PR TF shows that when we inject noise in yaw, there is a correlation with pitch. But this correlation doesn't seem to appear when we inject noise in pitch. Also, IM TF shows correlation between pitch and yaw wherever we send noise.

This confirms our first idea that one magnet of PR has probably fallen.

We then proceed to do some others tests.

First we used the "normal vi" and not the latest version which is not able to get a proper feedback.

Second, we check what happend when sending noise to each coil :

The coil number 3 of PR doesn't respond.

All BS coils seem ok but every coil impact both pitch and yaw (mainly yaw)

IM coils (2,4) move only yaw , coil 3 move only pitch but coil 1 doesn't respond.

EM coils seem good : coils (1,3) move only yaw, coils (2,4) move only pitch

Third we manage to align roughly the cavity again using picomotors.

Finally, after removing offset of local control, we could align the cavity using local control.

We locked the cavity but the stability doesn't seem to last for very long.

Finally, we could get all the references needed to be able to align the beam with the AOM.