[Alex, Cheryl, Deepak, Giacomo]

Yesterday, all ECDs have been set in place (position "2", i.e. 2 x 0.025" feeler gauges between magnet holder and bracket).

DC pitch of all optics has been set to 0 +- 0.5 mrad, except IM4 (set to pitch up by 4 +- 0.5 mrad).

All OSEMs have been centered, with the connectors (and the LED-PD line) in vertical, away from the optical axis. Although their relative position to the optic moved by some 50 um when we moved the suspensions in different positions on the table, clamped them and put the barrel on, all OSEMs can be set to read less than about 10 um by applying suitable offsets (basically showing that the "butterfly misalignment" is of this order). See data just after 17:45 local time on September 4.

We took TFs between about 6:00 and 7:30 pm yesterday, OSEMs' offset set to keep them centered and minimize non-linearities. Then left the suspensions undamped (but with offsets on) for the night. TFs and PSDs starting at 10:00 pm last night are attached.

Today I have spent most of the day trying to do a ringdown measurement on bounce, roll and transverse. I drove the "butterfly" mode at the frequencies previously measured for this mode, exploiting the parasitic coupling to excite them. I was able to excites all the modes, but I haven't had time to analyze the data yet. This are the relevant times for the excitations:

2012-09-05 12:28 Switching on "butterfly excitation" on IM1 and IM2. Amplitude = 10000 (per coil), frequency matching the measured one for bounce.

2012-09-05 12:50 Switching off excitation. Let it ringdown...

2012-09-05 13:57 Switching on "butterfly excitation" on IM3 and IM4. Amplitude = 10000 (per coil), frequency matching the measured one for bounce.

2012-09-05 13:19 Switching off excitation. Let it ringdown...

2012-09-05 13:32 Switching on "butterfly excitation" on IM1 and IM2. Amplitude = 10000 (per coil), frequency matching the measured one for roll.

2012-09-05 14:15 Switching off excitation. Let it ringdown...

2012-09-05 14:25 Switching on "butterfly excitation" on IM3 and IM4. Amplitude = 10000 (per coil), frequency matching the measured one for roll.

2012-09-05 14:47 Switching off excitation. Let it ringdown...

2012-09-05 14:55 Switching on "butterfly excitation" on IM1 and IM2. Amplitude = 10000 (per coil), frequency matching the measured one for trans.

2012-09-05 15:22 Switching off excitation. Let it ringdown...

2012-09-05 15:30 Switching on "butterfly excitation" on IM3 and IM4. Amplitude = 10000 (per coil), frequency matching the measured one for trans.

2012-09-05 15:50 Switching off excitation. Let it ringdown...

After the last measurement we removed the barrel and moved the HAUX in the middle of the table to make some space for HxTS testing.