kiwamu.izumi@LIGO.ORG - posted 05:40, Monday 23 May 2016 (27333)
A few more observations on the 0.5 Hz instability
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The instability occurs without a DARM offset (as expected).
- confirmed once with the interferometer locked on RF at 25-30 W
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At 25 W or a seemingly stable but high circulating power, aligning the pointing of the arms (aka soft degees of freedom) in situ lead to the instability.
- Or perhaps the in situ alignment took a long enough time to run into the instability. Not clear.
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The DRMI 2 omega RF signals seem to show a silimiar linear dependency to arms' dP/d(theta)
- could be a hint for localizing the position dependent loss?