TITLE: 02/13 Eve Shift: 00:00-08:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 68Mpc
OUTGOING OPERATOR: Cheryl
CURRENT ENVIRONMENT:
Wind: 4mph Gusts, 3mph 5min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.32 μm/s
QUICK SUMMARY:
TITLE: 02/13 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 71Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY: locked all shift
LOG:
I didn't feel comfortable with the extreme change in fill time for CP4 of late being just the increase in ambient temperature alone. As such, I decided to do another fill at the 48 hr. mark instead of waiting for the nominal auto fill which wouldn't be until Monday (72 hr. mark). Attached is the data. Any chance that we are seeing the needle/seat beginning to show signs of an ice ball obstruction? "I'm just saying!" As shown in the plots, I set the LLCV to 70% open for 30 minutes and then increased it to 100% open. The exhaust temperature finally responded 5 minutes after being increased to 100% open. I went out of the building and cracked the manual bypass valve and personally observed LN2 at the exhaust. I increased the nominal value to 44% from 42%. Note that I also verified that the valve stem pointer does agree with the CDS 4-20 mA output %open values so it isn't like the valve isn't opening etc... Also, the dewar head pressure is ~10 psi, which when combined with the liquid height should be more than adequate to make the elevation "hump" into the 80K pump etc..
Here is a plot over the year showing Dewar level correlated with LLCV setting. We changed the actuator this summer from pneumatic to electronic, and had to apply loctite to the valve stem threads because it kept trying to decouple from actuator stem; the calibration was significantly different from the previous actuator. Looks like LLCV was set to around 44% open during an almost empty Dewar back in Sept. so I think what we're experiencing here is a mismatch of LLCV setting to ambient conditions. Weather plays a big role and because it has been polar vortex cold we didn't have to raise LLCV as much during the winter and now we're back to "norm". We should double check the valve stem to make sure the loctite is still functional.
Description:
The one change I did not try was to change the bandpass filter back to FM1, where it was a week ago, from FM10 where it is now.
Plots attached:
TITLE: 02/12 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 70Mpc
OUTGOING OPERATOR: Jim
CURRENT ENVIRONMENT:
Wind: 2mph Gusts, 1mph 5min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.34 μm/s
QUICK SUMMARY:
ALL TIMES IN UTC
00:18 Tour into control room with Keita
00:28 a2l passive meassurement shows poor coherence in YAW. DARM also shows noise above reference betrween 12Hz and 25Hz.
02:53 Happened to notice a glitch in DARM between 40 and 100 Hz
05:00 ISC_LOCK guardian node went RED. Restarted the Node.
05:15 Been damping PI modes 27 and 28. Mode 28 PLL wasn't holding steady enough so I adjusted the set frequency from 255.00 to 255.6. This allowed me to have better control. This of course took the Intention bit down so I accepted the change in SDF and resumed Observing.
05:41 FINALLY turned mode 26 with -100 phase and 50K gain. Increased to -60 and 100K.
05:01:52UTC 70.623Mpc
03:56UTC Nothing showing in USGS or Terramon but a really sharp rise from ≈.01µm/s to ≈.8µm/s and then a rapid decay.
04:08 4.8 in Canada. We got sucker punched and didn't even know what hit us until 10 minutes after Lockloss. Courtesy of USGS
01:05 - 1:12UTC (roughly) Momentary loss of sanity. Reverted all SDF diffs and went back to Observing. Apologies.
00:49:44UTC Observing 1 hour standown time protocol. LLO and LHO are locked in coincidence.
TITLE: 02/11 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 71Mpc
INCOMING OPERATOR: Ed
SHIFT SUMMARY: locked entire shift, tried some damping on mode 22 and mode 23, and tried to damp mode 26
LOG:
more about modes 22 and 23:
TITLE: 02/11 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 68Mpc
OUTGOING OPERATOR: Jim
CURRENT ENVIRONMENT:
Wind: 3mph Gusts, 2mph 5min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.31 μm/s
QUICK SUMMARY:
Cheryl, Kiwamu, Sheila
This morning Cheryl went into the PSL and saw that the rejected beam from the thin film polarizer after the rotation stage was hitting the edge of the steering mirror which sends it to a beam dump. (She has nice photos of this). This aftrernoon she, Kiwamu and I went into the PSL to fix this.
We first adjusted the position of the iris after the bottom periscope mirror, and added two steering mirrors, and iris and a beam dump to the path to the OSA so that we would have good alingment references for the beam leaving the table. We then turned the power down before the PMC, and using base plates as markers moved the entire TFP assembly 5 mm closer to HAM1. Kiwamu took some photos of the resulting beam position on the steering mirror which are on Cheryl's camera. The beam was then high on the beam dump apperature, so we changed the spacer in the beam dump mount for a thicker one. We turned the power back up, and checked the beam on the irises and the persicope PD.
Cheryl's photos from this morning suggested that there could be clipping on the output apperature of the EOM. We tried to determine if this was clipping or a back reflection, but can't say for sure. Now we are out of the PSL, the IMC relocked without problems, and Jeff B has started inital alingment.
Kiwamu's image of the beam nicely centered after he and Sheila moved the houseing for the Thin Film Polarizers and the steering mirror.