Reports until 19:52, Wednesday 15 June 2016
H1 SUS (ISC)
nutsinee.kijbunchoo@LIGO.ORG - posted 19:52, Wednesday 15 June 2016 - last comment - 23:41, Wednesday 15 June 2016(27763)
Violin mode damping work update

Stefan, Nutsinee

So we found out that the ITMY vstop filter has been turned off. That's likely the cause of mysterious ring up of ITMY violin modes last night and tonight. I was able to damp the three highest modes (ITMY MODE2, MODE3, MODE5) with the settings on the table I confirmed on June 13. I haven't had a chance to re-comfirm all the settings. So until then I would either comment out IY violin mode damping guardian lines or just skip it for now.

 

Images attached to this report
Comments related to this report
nutsinee.kijbunchoo@LIGO.ORG - 20:04, Wednesday 15 June 2016 (27764)

Nevermind. I commented out every IY line except for MODE2, 3, and 5.

sheila.dwyer@LIGO.ORG - 23:41, Wednesday 15 June 2016 (27766)

Evan, Sheila

We tried the settings in the guardian (and in the new wiki) for ITMY mode 1 and mode 6, they worked so they are back in the guardian now.  ETMX mode7 (507.195Hz) is the largest violin mode now, and I don't see settings for this mode on the wiki, so I tried FM1, FM4, and a +30 gain (BP, 100dB, 0 degrees of phase).  This seemed to ring it up very slowly, so if we hadn't lost lock for unrelated reasons I would have tried a 60 degrees phase shift.