Reports until 22:51, Thursday 06 August 2015
H1 ISC (SEI)
sheila.dwyer@LIGO.ORG - posted 22:51, Thursday 06 August 2015 - last comment - 10:25, Friday 07 August 2015(20305)
Earthquakes, not much progress this evening, coil driver lockloss

Sheila, Gabriele, Nutsinee

Today I asked the operators to log when they do intial alingment and say what prompted them to do it, so I will start doing the same.

Tonight we had a trip of the ITMX ISI, stage 1 on the L4Cs, which was probably triggered by a PEM injection (which was unfortunately coincident with the arrival of a small earthquake).  After this, it seemed as though the alignment of the ITM might have changed. We had two locklosses durring CARM offset reduction, and DRMI alingment was bad.  After and earthquake, an ISI trip, and several locklosses, we decided to do inital alingment. 

After this we had one sucessfull lock, which I broke attempting to disengage CHARD so that we could phase refl WFS.  Then one and a half more earthquakes made us decide to call it a night without learning anything more about the violin mode. 

Note: We did add logic to the ISC_LOCK DOWN state that switches off ALL the violin mode damping, and added logic to the DRMI gaurdian (in engage DRMI ASC) that will prevent it from doing anything other than check for locklosses if SRM is misaligned. 

Also, earlier in the afternoon we had a lockloss that appeared to be because of coil driver switching. The lockloss seems to be coincident with BS M2 LL coil driver state changing. 

Images attached to this report
Comments related to this report
evan.hall@LIGO.ORG - 03:05, Friday 07 August 2015 (20308)

Not really sure what was going on seismically tonight... nono

Images attached to this comment
nutsinee.kijbunchoo@LIGO.ORG - 09:52, Friday 07 August 2015 (20317)

The three big peaks seem to coincide with three earthquakes in Mexico (5.3M, 4.9M, and 5.1M) arrived at LHO 21:47:49, 23:06:43, and 00:05:07 PDT (time of R-wave arrival). There was a 5.5M earthquake in Rwanda arrived at LHO around 19:36 PDT - around the time we started having trouble locking.

 

https://ldas-jobs.ligo.caltech.edu/~hunter.gabbard/earthquake_mon/seismic.html

hugh.radkins@LIGO.ORG - 10:25, Friday 07 August 2015 (20318)

The alignment shift from the BSC ISI Trip amounts to ~400nrads--see attached.  Something about half that for RY & RX and about maybe 150nm for Z.  No position DOF is restored for the BSC ISIs.   I also attach the Stage2 cartesian trends.  Z has a similar shift as Stage1 but the other are much samller.  Notice the trends of the tilt dofs (loops not closed) but for this 24 hour trend, it isn't much.

Images attached to this comment