Reports until 02:42, Wednesday 11 February 2015
H1 ISC
alexan.staley@LIGO.ORG - posted 02:42, Wednesday 11 February 2015 - last comment - 15:13, Wednesday 11 February 2015(16628)
Just shy of 2 hour lock

Sheila, Dan, Daniel, Evan Jeff, Lisa, Alexa

 

Starting at 08:43:06 UTC Feb 11, 2015 we had a DC lock for ~1:54min. We lost lock again because of the 9 Hz bounce mode in ETMY. We had tried damping with the L2 stage, which helped a bit but still ultimately caused the lock loss.  Tomorrow we should try damping with M0, as done at LLO (LLO#16686).

Comments related to this report
evan.hall@LIGO.ORG - 02:59, Wednesday 11 February 2015 (16629)
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Sheila has pointed out that we might as well notch out the bounce mode resonances in the DHARD WFS loops. So now there is a 9.8 Hz stopband filter installed in FM9 of DHARD_P and (in an abundance of caution) in DHARD_Y.

rainer.weiss@LIGO.ORG - 07:28, Wednesday 11 February 2015 (16634)
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Nice going with all the long lock segments. Once something is working
you learn a great deal quickly.
daniel.hoak@LIGO.ORG - 15:13, Wednesday 11 February 2015 (16659)
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Some important times from the lock:

Lock sequence started at ~8:17 UTC when arms locked on green

Handoff to POPAIR at 8:27 UTC (this is the last step in the ISC Guardian before the handoff to DC readout - see LSC matrix element 3_10 in the attached plot)

DARM offset applied and OMC locked at 8:40

DARM handoff to DC readout at 8:44

Lock lost at 10:36 UTC

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