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Reports until 10:58, Wednesday 29 June 2016
H1 IOO (IOO, SUS)
cheryl.vorvick@LIGO.ORG - posted 10:58, Wednesday 29 June 2016 - last comment - 11:07, Wednesday 29 June 2016(28051)
changes to IMC alignment after Mantenance: largest is -44urad on MC3 P

In looking at HAM2 optics, I noticed that all three IMC optics, MC1, MC2, and MC3 have alignment changes from before to after Mantenance yesterday.

  change in alignment  
MC1 P +25 urad
MC1 Y +20 urad
MC2 P +3 urad
MC2 Y +3 urad
MC3 P -44 urad
MC3 Y +15 urad

Sliders did change, however I can see where the old safe.snap alignment offsets were loaded, and then corrected, for MC1 and MC3.  MC2 is odd because I don't see where the safe.snap alignments was loaded since it's alignment offsets are not seen on MC2 in the same time frame.  I started my plot at 6/28 at 15:00UTC which is 8AM local, when Maintenance starts.

IM4 Trans pitch and yaw also changed by 0.02 (+ for pitch, - for yaw).

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cheryl.vorvick@LIGO.ORG - 11:07, Wednesday 29 June 2016 (28052)IOO, SUS

DAC cards were changed for MC1 and MC3 yesterday, so this is a plausable expalnation for the large change in MC1 and MC3 OSEM readouts - electronic offset changes.

MC2 DAC card was not swapped, and it's OSEMs show a change of pitch and yaw of 3urad, and the IMC is stably locked, and IM4 Trans shows only a small change, so that suggests that MC1 and MC3 pitch and yaw alignments changed by much less than the 25-44urad seen on the OSEM readouts.

IM4 Trans shows some alignment change of 0.02 on pitch and yaw, so this is noticable but much smaller than a 0.1 change that would warent more investigation.

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