Krishna, Michael

We took a look at the noise of BRSX with damping forced on and off now that the new damper is installed. For context, the previous damper injected lots of broadband noise which made the BRS unusable during damping. The first plot in the attachment shows that with the new damper we get comparable tilt subtraction whether the damping is on or off. The second plot is a more broadband view of the BRS noise and shows that the damping rings up the torsional mode (~3 Hz) and some other higher frequency modes but doesn't change the broadband noise. The wind picked up right when we forced the damping on so there's an overall increase in low frequency motion.

After taking the measurements with the damping forced on (~1 hr), we found that the BRS had started drifting rapidly which decreased the ability to subtract tilt. This is due to the heat generated by the stepper motor that drives the turntable. In normal operating conditions, the damper shouldn't ever need to run for this long and thus shouldn't create such a large of a drift.

The take away from this is that the BRSX sensor correction need not be turned off if damping does trigger. The tilt subtraction might not be very effective shortly after damping but it should still be useable.

Michael, Krishna, Jim, Hugh

Here's a brief look at the performance of the BRSY sensor correction during Wednesday's ~20-40 mph winds. We were using 250 mHz blends and Warn_SC_2 sensor correction filters for Y axis (the beam axis). The interferometer was able to lock well as noted in 27658.

The first plot in the attached pdf shows an ASD of the ground seismometer Y, the BRS rX, the tilt-subtracted seismometer Y and the ST1 seismometer Y signals. The tilt-subtraction worked well and kept ST1-Y motion small even as isolation was provided above 0.1 Hz from the sensor correction filter. Note that ST1 still sees the ground tilt and the seismometer output is contaminated by tilt, hence the effect of the isolation is not clear in the ST1 Y channel but we expect it to be there. Ideally one would like to measure the tilt going into ST1 from the ground and cancel that (rX sensor correction), but as Robert showed in his alog a few weeks ago, ground tilt varies significantly on the LVEA floor and one would need multiple angle sensors to map it well or one (good) angle sensor on Stage 1.

The second plot shows the coherence between the ground seismometer Y and BRSY rX and that between the tilt-subtracted Y and BRSY rX. The high coherence in the first is good, but the high coherence in the second indicates that the tilt-subtraction is not optimal yet and improvements of ~2 could be had at low frequencies.

The third plot shows has the same lines from the first, along with the buried seismometer Y for comparison. One can see that the tilt-subtraction is more effective and is also more useful above 0.1 Hz.

The fourth plot has two additional lines - ST1 CPS and it's RMS. The RMS motion was kept below 1 micron but had an odd bump at 8 mHz. Jim and I tried to add a notch to the sensor correction at 8 mHz but were unsuccessful in suppressing it well.

This morning I modified the high pass filters for the tilt-subtracted seismometer channels as shown in the second attachment. The new (red) filters suppress signals below ~20 mHz with some gain-peaking at 40 mHz (which is acceptable) and decent phase above ~60 mHz. These seem to work well and keep the CPS signals small. They are installed at both ETMX and ETMY. The third attachment shows the sensor correction with this new filter . The wind-speeds were only ~10 mph but the CPS signal is smaller and doesn't show the ~8 mHz peak.

Will comment this entry when leaving

We are still losing lock more than 50% of the time once we start to increase the power into the interferometer. I slowed down the rotation stage to 10% of its normal speed. In this way I was able to make it to 10 W once. On the second try, the interferometer lost lock right after a gain step in the summing node board. The behavior of the CARM error signal does not seem any different from past successful power increases, so it is not clear to me what could be wrong with the summing node board.

In order to make it easier to engage the soft loops, I made the 20 dB boosts come on only when the soft loop error signals are less than 0.01 ct.

I also turned down all the hard loop gains by 6 dB and re-engaged the bounce mode notches in the suspension PUM drives, because the bounce modes were becoming unmanageable.

TITLE: 06/11 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: None
SHIFT SUMMARY:  We have had good locking all night, getting to INCREASE_POWER for the first time in a long time.  It has been a bit windy, but just under the threshold for locking. 
LOG:
Locking, commissioning, locking, commissioning . . .  Mostly keeping Evan company.

As noted in alog 27683, turning on the 10dB gains in the M0 Lock filter banks for increased offloading speed was killing the lock. We saw that again today.  I turned on all the filters by hand, and it seems that it's the ETMY Y that is the problem - all others are fine.  Sheila pointed out that ETMY has filters for Y2Y and P2P in the M0 drivealign banks, but no other quads do.  We turned off the invY2Y filter, and we were able to run the EngageSoftLoops state.  We didn't turn off the invP2P, but we probably should so that all the quads are the same.

Title:  06/10/2016, Day Shift 15:00 – 23:00 (08:00 – 16:00) All times in UTC (PT)
State of H1: IFO unlocked. ITMX ISI Stage 2 WD tripped. ETMX RMS WD tripped. 
Commissioning: 
Outgoing Operator:  None
 
Activity Log: All Times in UTC (PT)

14:48 (07:48) Reset ITMX ST-2 WD trip.
15:00 (08:00) ETMX RMS WD tripped. 
16:16 (09:16) Kyle – Going to Mid-Y for CP3 fill
16:21 (09:21) Richard – Going to End-X to work on RMS WD
16:30 (09:30) Kyle – Back from Mid-Y
16:36 (09:36) Ed – Going to Mid-Y to look for test board
17:04 (10:04) Ed – Back from Mid-Y
17:05 (10:05) Richard – Back from End-X – The RMS WD has been reset
17:35 (10:35) Karen – Cleaning the H2 building 
17:37 (10:37) Richard – Going to End-Y CER
17:48 (10:48) Richard – Finished at End-Y
19:15 (12:15) Sheila & Ed – Going into squeezer bay looking for electronics
19:34 (12:34) Sheila & Ed – Out of LVEA
20:39 (13:39) Ed – Going to Mid-Y
23:00 (16:00) Turn over to Travis


End of Shift Summary:

Title: 06/10/2016, Day Shift 15:00 – 23:00 (08:00 – 16:00) All times in UTC (PT)
Support: Jenne, Sheila, Jim, TJ
Incoming Operator: Travis

Shift Detail Summary: Reset ITMX ISI St-2 WD. ETMX RMS WD is tripped. Per aLOG entries tried toggling the Reset from 1 to 0 back to 1. No change. Cannot lock X-Arm until this is cleared. RMS WD is reset. Did an initial alignment, and started trying to lock. Commissioners continue working through various locking problems

Some time ago one of the water manifolds for the laser failed.  In dismantling the manifold,
traces of PTFE tape are evident in the bores of the flow meter and pressure regulator.  There
are no signs of the anodising from the homogeniser or fibre bundle holders in the fittings.

I had a look at lock loss times and their durations during O1 (only lock losses from nominal low noise). I've had a brief look at a couple of the physical environment channels (H1:PEM-EY_WIND_ROOF_WEATHER_MPH for wind and H1:ISI-GND_STS_ITMY_Z_BLRMS_100M_300M for seismic) to see how they are correlated to these lock losses. There are a few plots I've attached here below. All of the data for these plots are mean minute trends

Plots:

Duty_cycle_noncumulative.pdf  - This is a 3D plot showing the duty cycle for different wind and seismic bins (percentiles)
Duty_cycle_cumulative.pdf   - This is a 3D plot showing the duty cycle when the wind or seismic behaviour is greater than or equal to the given percentiles 
Downtime_wind_seis.pdf  - This is a 3D column plot showing the integrated 'downtime' that results from a lock loss in the given wind and seismic bins (percentiles)
lock_losses.pdf  - This plot shows the number of lock losses per percentile bins, surf (matlab) makes it look a bit weird. 

I've also attached lock_losses.txt which is a list of the times in GPS when the lock losses occur (first column) and their duration in seconds (second column). The durations and loss times are only to the nearest minute unfortunately since I used minute trend data.

Percentiles.txt contains the wind (first row) and seismic (second row) channel values that correspond to 5% intervals starting from the 0th percentile (0,5,10...). These are for the mean minute trends though which are much lower than the maximum minute trends. 

I have built a 24-hour version of SenseMonitor on the redundant machine
(h1dmt2) and it is apparently running now. I also modified it to
initialize the dmtviewer time series from the minute trends (this should
get rid of the errors that showed up every time the dmt was shut down
without stutting down SenseMon cleanly in advance). This version is
available right now as the SenseMonitor_rhoft_H1 monitor. If it looks
like it is working well, I will make this version the default.

A few notes:
 a) as of now, the the rhoft version will not come back without a little
fidgeting. Let me know it stops working.
 b) because of (a) it would be good to get a definitive statement about
whether this is what is desired so I can install the modified code.
 c) Jim requested that the _CAL_ version be modified but I changed the
_hoft_ version. This was purely for ease of testing. Once I install the
new executable, all versions will be 24hours. If you want some to be 24
and some to be 12 hours, I can fix that by juggling configurations.
 d) Yes, Chris and Vern, This means that I can now start up a BBH SenseMon.

Attached are two illustrations: The first is a notional schematic of the pum rms "watch dog" showing the interconnections between the rms circuit, the "trigger logic", and the driver amplifier. The second drawing shows the signal levels through the circuitry.  The information for these illustrations came from drawings D070483, PUM Coil Driver Sheets 1 & 2, and D0900975, Monitor Board.  (The D0900975 is an annotated update of the old D070480 Monitor board.)

The resetting of the rms-wd is accomplished by either powering off, waiting a minute, and powering back on, which allows the reset circuit (R17, R18, C18, and U15B) to clear the D-flip-flops or a High-to-Low voltage transition on P18 of connector J7 on the PUM Coil Driver card.  There is a binary I/O and software (MEDM button) available to do this remotely.  Richard M. and Fil C. are checking the integrity of this.  The state of the trigger D-flip-flops (tripped or not-tripped) is available on the MEDM screen for the PUM drivers.

Sheila, Evan, Carl Terra

At the end of the night we had several locklosses when trying to engage the soft loops.  It seems like the problem could be turning on the 10 dB more offloading gain in the top mass, which we have been doing without a problem for several weeks now. In the last lockloss like this, L2 rms watchdogs tripped on all 4 test masses (not all coils).  Evan manually reset the Y arm optics, but we couldn't reset the X arm optics.  For ETMX, Terra and I went to the end station and tried power cycling the coil driver, but this didn't allow us to reset the watchdogs. Carl and Evan power cycled the ITMY coil driver, and were able to reset the RMS WDs but the software WD cannot be reset.  

Also, we have had several EQs tonight (both large and small) and tried out turning sensor correction on and off.  

Bounce damping setting was changed for IY and EX so they damp at all. Don't know why the old settings don't work.

For EX I just flipped the sign.

For IY, I rotated the phase by 210 degrees in effect and increased the gain significantly. Gain increase might be unnecessary but I leave it like that because it seems to work faster.

ISC_Lock was changed but not loaded.

ETMX Mode3: FM1, FM2, FM4,  +10 gain (BP, -60deg, 100dB) seems to have worked quite well. No need to turn on a damping for 505.707 (which should be checked again with 0.0001 BW to see if it's really exists). 505.707 should be watched while damping 505.710 just in case.

The new violin mode table is being uplated slowly. The modes with Damp Setting column filled out are the one that's been sucessfully damped by the filter settings indicated in the table.