nutsinee.kijbunchoo@LIGO.ORG - posted 22:59, Saturday 09 July 2016 - last comment - 02:54, Sunday 10 July 2016(28310)
Finally locked at NLN
Intent bit set at 05:30 UTC. PI modes are not well damped but they're controlled for now. There are few weird things I noticed about some of the PI modes:
- ITMY MODE 2 (14979 Hz) will start off ringing up no matter what gain I used. The nominal gain setting for this mode is +300, I flipped the sign to -300 stopped it from ringing up (and managed to damp the mode). So I updated PI guardian accordingly. However, when I went to INCREASE_POWER (after a lockloss) the mode started ringing up again. So I flipped the gain back to +300 and returned guardian setting to what it used to be.
- ETMY_PI_OMC_DAMP_MODE6_RMSMON corresponds to 18041 Hz. However, the line is not visible in DARM ASD plot. I had to put faith into whoever design the monitor and blindly flipped damp settings around. Luckily it worked.
- ETMY 15009Hz has been causing both Jim and I problems today. I was able to finally keep the mode under control with +60deg (instead of -60deg which was the nominal setting)
As I was writing this alog, the ifo went DOWN because of ETM bounce mode (not sure which ETM, possibly both). I didn't put them on my StripTool since I was assume only ITMX has problem. Huge mistake...
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Locked again at NLN. Intent bit switched to Undisturbed at 07:22 UTC. I'm going to stick around a bit to keep an eye for the bounce mode and PI. PI modes are somewhat under control. Bounce and Roll modes seem pretty well damped at this point.
Hence a beautful ending of ER9.
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The IFO lost lock and relocked itself after I came home so the intent bit is no longer set. It would be nice to have a way to set the intent bit remotely.