WP 6179 F. Clara, J Batch The rear panel power switch for the I/O chassis for h1lsc0 was replaced this morning, the h1lsc0 computer has been restarted.
* First 4 hours of today declared maintenance * SEI: Tue: Investigate elevated CPS noise on BSCs. Power cycling boards, etc. Takes ISIs down. PSL: Separate breakout meeting before commissioning meeting to address periodic tripping off of PSL. TCS: Possible water problem on TCSY. Check table today before going laser safe tomorrow. VAC/FAC: Tue: Crane scissor lift. Request for laser safe Tue. CDS: Fix bad pin on AS-C QPD whitening chassis. Photographer for Science magazine back tonight Jeff B.: Check all dust monitors on site (time permitting)
I attach a plot showing several flow sensors and flags around the time of the latest PSL shutdown. The power meter flow sensor channel (thought to be responsible for the shutdown) has a strange constant oscillation that does not stop when the flow does, and it doesnt go to zero. It doesnt seem consistent with an air bubble shutdown and may need replacement or there may be problems with the data acquisition.
TITLE: 10/02 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: DOWN due to PSL
INCOMING OPERATOR: Corey
SHIFT SUMMARY:
The PSL continued to have issues today & decided to cancel EVE & OWL shifts tonight. Did make it to NLN twice (PSL trip ended both) which is nice (ITMy Bounce must be gone).
LOG:
With the PSL only able to operate for an hour or so at a time, it was decided to work on the PSL TOMORROW and cancel the EVE & OWL shifts. (Jason consulted with Vern & I've been in contact with Daniel, Mike, & Vern via email.)
Was just getting ready to post an alog saying we've been in NLN near 60Mpc and that Robert was going to do injections, but the PSL tripped as I opened the alog....going to call Jason...after I have lunch.
15min at NLN, here are notes on DARM:
Completed Recovery in ~30min with Jason on the phone. Back to locking at 12:42pm.
NOTE: LRA, stands for Long Range Actuator.
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.
Tasked by Kiwamu and Stefan to turn random knobs in a hope of getting rid of 100-1kHz bump, I was able to gain 15 Mpc by adding -0.05 offset to CSOFT pitch and yaw. I haven't had a chance to try every ASC knobs due to the power glitch. We were at 75 Mpc before the IFO went down.
Here's a note on everything I've tried (all time in PT):
3:40 added/subtracted 0.02 counts to H1:LSC-MOD_RF45_AM_RFSET -- Nothing improved
3:46 Added +6 gain to PRC1 LSC -- 27 Hz line became visible. But later found this line to come and go so this could totally be a coincidence
3:52 Changed CO2X power to 1W -- quickly dropped the power back to nominal when I realized that it's probably going to take a while to see the result
4:38-4:58 [In ASC land] Played with CSOFT pitch and yaw offset -- Settled at -0.05 for both. Slightly improved overall DARM spectrum but made 20-30 Hz wrose. Gained 15 Mpc in range here (if it's not calibration that's fooling with me). Any more negative number added would decrease AS90/POP90.
5:06 Added -10 to CHARD pitch -- nothing improved
5:13 Added -0.07 to CSOFT pitch -- nothing improved
5:14 Added -20 offset to CHARD yaw. -- Nothing improved
5:17 Added offset to DHARD pitch -- Nothing improved
5:27 Added offset to DSOFT pitch -- Nothing
5:48 Added -0.05 offset to DSOFT yaw -- Increased AS90/POP90 but no obvious approvement in DARM.
5:58 Added -25 offset to INP1_Y -- improved AS90/POP90 but no apparent improvement in DARM spectrum
6:08 Power glitch. Meh.
I also moved PR3 and changed something on SRC1 but didn't write down details (since it probably was not doing anything).
I put everything back in place before the power glitch except for the CSOFT gain that worked. I turned off all the gain buttons that I turned on except for CSOFT P and Y but not neccesary return the gain number back to what they were. I have them all written down though.
