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Reports until 17:44, Tuesday 01 May 2018
H1 SEI
hugh.radkins@LIGO.ORG - posted 17:44, Tuesday 01 May 2018 (41785)
WHAM4 ISI TFs lead to Table rebalance

After the SR2 Baffle swap, the TFs on the ISI looked all good, except, V2.  GS13 was saturating and above the resonance the coherence really dropped out.  Suspecting the balanced changed enough to get the lockers close enough to start hitting, the CPS positions were checked and the balanced was in fact changed by 100 & 50 urads in RX & RY.  Does not really seem like a lot when you consider the ISI lockers have a clearance of 600um on the radius.  The three vertical local sensors shifted 2000, 1500 & 500cts,  hmmm not sure the calibration off hand.  But the weird thing is the ISI actually went down in the corner were the baffle was replaced with one with a larger hole (less material, you would think.)  Anyway, pulled 200 grams off the SE corner and put 100 of it back on the NW corner and 50 on the SW corner.  This shift put the ISI right back where it had been.

TF for V2 looked good but then the V1 and V3 TFs went south.  There is a lot of purge going on and checking the cover, sure enough it had popped off our cover holder but there was so much purge the cover was not touching anyway.  Latest look has V3 looking okay but V2 and V1 looking pretty ratty.  Like to reserve final judgment now after a closer scan in chamber and TFs with less purge.  Crew is back in HAM5 right now so will regroup in the am.

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