TITLE: 10/31 Owl Shift: 07:00-15:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Ed
SHIFT SUMMARY:
Locked for most of the shift. 4753Hz line was slowly ringing up so I reconfigured the damping filter. Range were up and down likely due to wind. Lockloss seems to coincide with ~40 mph wind gust. PI mode18 rang up once, flipped the phase sign and never saw it again. Verbal alarm complains about TCSY chiller flow towards the end of shift but this is bogus. As Kiwamu requested I also increased CO2 power thoughout the shift, 90 minutes at a time.
LOG
08:33 Increased CO2X from 0.2W to 0.3W, CO2Y from 0W to 0.1 W
9:18 Got an unknown external call
10:04 CO2X 0.3-->0.4W, CO2Y 0.1-->0.2W
11:35 CO2X 0.4-->0.5W, CO2Y 0.2-->0.3W
13:06 Co2X 0.5-->0.6W, CO2Y 0.3-->0.4W
13:40 Intent bit dropped for a second due to Guardian code load
14:11 Lockloss. SRC1 suddenly ran away. Coincide with ~40mph wind gust but this happened before earlier in the shift without breaking the lock.
Got a verbal alarm complaining about TCSY chiller flow so I went out to check the chiller on the mezzanine. At the TCSY chiller itself reported flow rate to be ~4Gpm. I also went out and check the mechanical flow meter in the LVEA and it appeared to be reporting >3Gpm. I don't know why the flow channel (H1:TCS-ITMY_CO2_FLOWRATE) is reporting something bogus.
The mode is made of two lines, 4735.05 Hz and 4735.09 Hz. Not sure why I didn't see this before. I increased the BP to be 1 Hz wide so the phase change between the two lines are not too far apart. Now damping at -60 deg phase, 0.02 gain.
Robert and I tried using Stefan's PR2 move and PR3 move states while Robert had a shaker on near HAM2. We ddin't suceed in reducing the noise at the injection frequency, but we did find some POP offsets that gave us better recycling gain:
We got a recycling gain of 33 (35 according to the transmission QPDs) with POP A at -0.24 for pit, and -0.26 for yaw. This didn't have much of an impact on the noise once I reran a2L.
For now I'm leaving the offsets at the values we have been using (0 for Pit, 0.44 for yaw offset) because that is the position where we can power up without a braodband lump from 200Hz -1kHz. With the higher recycling gain we didn't get a lump, but we did start to have coherence with DBB QPD1Y.
A quick request for operators:
Let's try a test of running the a2l test every lock. If you see that the low frequency noise is degrading over the course of a long lock, you can rerun it to see if that helps.
As a reminder:
get to nominal low noise
go to userapps/isc/common/scripts/decoup/
type: ./a2l_min_LHO.py
8 lines around 20 Hz will appear in the spectrum and slowly get turned off one by one as the script becomes satisfied that it is done with each optic.
I did a scattering scan for the entire site, including mid-stations, with a focus on the 50-200 Hz region and on sites that had previously been identified as potential scattering sites in scattering photos (e.g. https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=9564 https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=8281). The worst locations were between the chamber and the gate valve at the end stations (probably similar to what has been seen at LLO) and the input arm, especially between HAM2 and HAM3. The scattering at these three locations was close to showing, or showing in DARM, I can not be sure yet, study of these sites is ongoing. At EY I put black glass in each of the ports, which did not change the scattering peaks I was enhancing with a shaker. I thought the difference with LLO might be that there were no aluminum blocks in any of the LHO ports, so I inserted one in each of the ports but this did not make the coupling worse. We should try black glass at all ports simultaneously, and there are some other tests I would like to do.
At the input arm, the scattering noise, enhanced with a shaker, was clearly modulated with a 0.02 Hz yaw injection at PR2. I observed the input arm through multiple ports and found two spots that especially concerned me, both visible with the digital cameras after I adjusted them: the baffle in front of PRM (see photo) and around PR3.
TITLE: 10/30 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: Jim
SHIFT SUMMARY:
Robert had H1 for a good chunk of the day & Jenne had it for a lock or two. Other than that, just working on keeping H1 up for commissioners.
LOG:
Whoops---just dropped out of lock. at 18:40 (11:40am).
Taking IMC to MISALIGNING state so Robert can do some non-locked measurements.
To prevent splashing of light,
no fibers shutters, EY swapped, see alog 30624.
TITLE: 10/30 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: Cheryl
CURRENT ENVIRONMENT:
Wind: 9mph Gusts, 6mph 5min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.26 μm/s
QUICK SUMMARY:
State of H1: relocking
Shift Details / Activites:
Notifications:
State of H1: relocked and in Nominal Low Noise, Range is 68MPc
Activities:
11:08UTC - bad click, broke lock, was making slow progress with bounce and roll
We chose to set the AlignIFO node ready for locking the arms in LockingArmsGreen. Since the Down state is mostly stuff to stop actuation when we lose lock, we don't touch the AlignIFO node in that state. Once you get to LockingArmsGreen, immediately after Ready, the ISC_LOCK guardian will set the AlignIFO node appropriately.
State of H1: SEI in LARGE_EQ_NOBRSXY, ground motion increased to 10um/s
Help: JimW changed SEI settings to EARTH_QUAKE_V2, and explained the use of LARGE_EQ if ground motion got worse
Details: