15min at NLN, here are notes on DARM:
Level was at 5.4cm. Took 250mL to get it up to 8.9cm. (Nutsinee last filled at ~3am with a similar amount)
(Corey, Jason on phone)
Last night, Nutsinee came in early for her OWL shift & just before midnight the PSL tripped. We opted to leave it tripped for the night to wait for Jason to walk us through recovery procedure. Atleast for now, we always want to run through this procedure with one of our PSL people (Jason or Peter K). Here are my rough notes:
Now on to "Aligning" on Observatory Mode!
PSL Status NOTE:
The Xtal chiller has tripped 3 times in the last week:
then 4 days later:
now 3 days later:
The last two events imply an overpressure condition. The problem seems more significant than replacing lost fluid from a slow leak.
Was the cap which "blew off" in today's event the "bleeding cap" (section 4.2.2), the "filter sleeve cap" (section 6.2) or the "filler pipe cap" (section 6.3 of T1100374-v1, "200 W Laser Crystal Chiller Manual")?
BTW, LRA = Long Range Actuator; see section 7.2 of T0900641-v5, "Under Manual 200 W Laser".
From my quick look through the alog I think the PSL has tripped more than this (for LHO to concur). From what I can see it has gone off 11 times in the last week (thats as far as I looked back).
I'm not sure if all the same problems, but alogs reporting the PSL laser off are LHO alogs:
10/2/2016
LHO alog 30160
LHO alog 30154
10/1/2016
LHO alog 30146
LHO alog 30143
9/30/2016
LHO alog 30118
LHO alog 30086 (due to power glitch)
9/29/2016
LHO alog 30076
LHO alog 30063 (this alog reports two different instances of the laser going off)
9/27/2016
LHO alog 30016
9/25/2016
LHO alog 29964
The filler pipe cap popping out is a known thing (happens all the time at LLO) when the chiller turns OFF. At LLO at least this has not shown to be due to any problem (just a consequence for whatever reason when the chiller is turned off). Its why we try to not turn these chillers OFF if can help it as they "burp" water over the floor and pop these fill caps even when trying to restart
I have as one of the main agenda items of this Wednesdays PSL meeting to discuss this problem and see if we can work out whats going on. Some statistics on how many times happened in say the last month or two, what the PSL trip was attributed to, and how many times happened before and after the chiller swap (to see if accelerating or at the same rate), would help this. Im not sure if FRS fault reports have been made for each laser trip to make this search easy for us remote to the site to do and work out how much lost observatory time we have had due to this issue.
Yes, Dennis, as Matt says it's the Filler Pipe Cap that pops off. We have had (3) trips since Friday evening (so Matt is probably right about there being more trips over the whole week). OH, and I should correct ourselves here because we just had a 4th Weekend PSL trip (this was just after I had H1 at NLN for 15min. This time the cap was blown off and there was a puddle on the floor.
Able to get back in 30min this time (vs 60min this morning).
OK, back to locking.
Another Note:
Something I wanted to add about the chiller was that when filling it, I noticed quite a bit of turbulence in the fill pipe. And you could see a air bubble vortex/tornado in there. Something we probably don't want if air bubbles are postulated as a trigger for flow sensor trips.
We see these bubbles as well in the chiller fill pipe at LLO with no chiller trips due to it (hopefully haven't jinxed myself). Perhaps post a movie of it so can see if looks the same as here
Jason & crew will be investigaing tomorrow. We should ask them to record a video of it.
Movie of the water turbulence of LLO's crystal chiller fill tube posted at LLO alog 28397
I took a video, but I can't post it; my phone only takes video in .mp4 format, which is apparently not a valid file type for upload to the alog. Huh.
I attached a still from the video to give you some idea of what we've been seeing here for the last few weeks. It's appearing to fluctuate though; the video was taken on Monday, 10/3/2016, but this morning our fill port looks very similar to what's seen in Matt's video of the LLO crystal chiller fill port.
TITLE: 10/02 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Unknown
OUTGOING OPERATOR: ...No full OWL shift
CURRENT ENVIRONMENT:
Wind: 10mph Gusts, 6mph 5min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.10 μm/s
QUICK SUMMARY:
PSL tripped again last night. Talked with Ed & Nutsinee about it during their shifts. Have sent an email/text to Jason about bringing back the PSL & will address soon (Ah, Jason just texted back. He'll walk me through the procedure over the phone momentarily.)
Then we'll see how H1 is after an Initial Alignment....hopefully ITMy Bounce is less bouncy.
What Else: Robert is here.
Got a TCSY low flow rate alarm so I went out to check on the chiller. Water level was at 5.6cm line. Added 250 ml. Now at 9cm.
I've tried calling several people who I believe know how to untrip the PSL and might still be awake but non picked up my call (except for Ed, he had only done it with Jason walking him through so he couldn't help me). I also was told that the PSL card in the key box cannot access chiller diode room.
I will hang around the control room for a little bit to see if anyone calls back.
04:03 at last lockloss upon returning from filling the TCS chiller i found the PSL tripped off again. Jason talked me down and evrything is back on and the subsystems are all locked and happy.
Didn't bring a pen with me so the paper log isn't filled in.
After about a 2.5 hour standown time I started Initial Alignment at ≈ 02:00UTC. I started locking the IFO at ≈02:48 and got to ENAGE_REFL_POP_WFS. The bounce mode is still "bouncing" so I decided to play with the damping filters a bit. Nothing I did really made a difference in the DARM peak until, of course, I clicked once too many times and broke the lock that I had. Stefan popped in for a brief while with Alexa (yes, that's right....Alexa) but they seem to be gone now. I'll inform Nutsinee that I probably won't be staying much longer as I won't be able to do much with this situation and no other commissioners are due here, that I recall.
TITLE: 10/01 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1:
INCOMING OPERATOR: Ed M.
SHIFT SUMMARY:
Guardian was back, but so was a troublesome ITMy Bounce Mode. Currently leaving H1 DOWN in an attempt to let it ring down.
LOG:
The bonce mode was rung up vey high today (>1e-13m RMS in DARM). Worse yes, anything I tried to do just seemed to make it worse.
I tried both previous settings (see Keita's and Jenne's alogs below), but I was just ringing it up more.
The measured frequency today was 9.8320+-0.005Hz.
In the end it was so bad that the ITMY kept saturating, so I decided to leave the interferometer down for a feq hours.
Keita's elog on ITMY damping: 27680
Jenne's elog on ITMY damping: 29888
As we tried to go up to LOWNOISE ESD ETMY earlier, we could clearly see several lines on the DARM spectra and these were traced to a BOUNCE mode (ITMy to be exact). Stefan has been trying various gain changes & filter changes, but everything seemed to just excite the mode more.
Right now we're turning off Locking to let the system quiet down. Then we'll get back at it.
Completed Recovery in ~30min with Jason on the phone. Back to locking at 12:42pm.
NOTE: LRA, stands for Long Range Actuator.