Reports until 22:14, Wednesday 19 September 2018
H1 SEI
sheila.dwyer@LIGO.ORG - posted 22:14, Wednesday 19 September 2018 - last comment - 08:28, Thursday 20 September 2018(44068)
ITMY ISI motion/ ALS trouble

We are having trouble keeping the Y arm locked in green right now, and according to the optical lever ITMY is having large sudden glitches.  Our difficulty locking might be unrelated to the apparently higher motion of this ISI, which has been moving more that ITMX for 20 days according to the BLRMS. 

The colored blocks on the ISI overview screen seem to indicate that there is a problem with the ISI, and Corey noted that the CPS spectra looked noisy earlier today.  (44061)  

I think that Jim looked into that and I think he and Betsy told me that the problem came and went, indeed.  The first attached screenshot shows a comparison of the 4 BSC ISI BLRMS medms. (ETMX has a known problem, ITMY has only starting having this problem as far as I know.)  Also attached is a time series of some of these BLRMS with a couple of the ITMX channels for reference.  There does seem to be some kind of a problem that might be coming and going on ITMY, this has been the case for at least 20 days (3rd screenshot). 

 

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corey.gray@LIGO.ORG - 08:28, Thursday 20 September 2018 (44071)

Attaching snapshot (1st attachment) of ETM & ITM BLRMS colored blocks (similar to what Sheila posted) for current time and ITMy looks quieter for the moment.

On the ITMY Summary Page (2nd attachment) you can see some noisy periods from 5pm to current :

  • 7-10:30pm
  • 11:30pm-12:30am
  • 2:30-5am
  • Looks quiet currently

Hugh & Jim will probably be making a trip out to investigate CPS for ITMy ISI & check electronics.

Will not generate an FRS since there is already one for the CPS from yesterday.

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