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Reports until 15:45, Wednesday 06 July 2016
H1 IOO (IOO, SUS)
cheryl.vorvick@LIGO.ORG - posted 15:45, Wednesday 06 July 2016 (28200)
IO IM2 shifting alignment with lock aquisition and lock loss

The first plot shows IM2 pitch changing by as much as 0.4urad at lock loss (lock loss after IMC power oscillations).

Subsequent lock losses on the plot show it moved by 0.3urad, 0.2urad, 0.2urad,and 0.2urad, for an average change in alignment of 0.26urad at lock loss from a 40W H1 lock.

This result supports my theory that the beam on IM2 is no longer centered, and is off center enough to explain the oscillations in it's pitch and yaw signals that I aloged here, and in an attachment here (where I showed that IM4 Trans sees the oscillation), while the IMC was oscillating in power from 22W to 57W.

The second plot shows that when H1 was no longer locking, the jumps in IM2 alignment stopped.

Images attached to this report
Displaying report 1-1 of 1.