The IFO has been having troubles with ASC instabilites yesterday and this morning, Elenna and I will write an alog about what we did this morning.  These seem to be new problems, and so I was wondering if they might be caused by a change in suspension response, escpecially because we've had trouble with the ETMX suspension. 

I measured the optical lever response to an ASC excitation for all 4 test masses, resuts attached. For PIT, ITMX response is a factor of 2 below the other test masses.  I ran the baffle align script for both ITMs, to check the optical lever calibration, and it seems that the ITMX oplev calibration is wrong.  43816 says that the angle between pointing the ITM to baffle PD 1 + 4 should be 37.2 urad pitch and 37.4 urad for yaw.  According to the optical levers ITMX moved 40 urad in pitch and 15.7 urad in yaw.  This factor of 2 calibration error in yaw explains why the transfer functions look mismatched. 

ETMX isn't an obvious outlier in either pitch or yaw, so this test doesn't offer an obvious explanation for our ASC instabilities.