Terra, Sheila

After recovery tonight we did a few things:

• Reduced the gain of the PRC2 loops, by a factor of 5 each. (PRC2 P gain from -5000 to -1000; PRC2 Y gain from -10000 to -2000) because we saw an instability at around 1.5 Hz that could be reduced with the lower gain.  These loops have had higher gain than normal the last few weeks (the story is here)
• Reverted the TMS matrix to the one that is insensitive to transmon motion.  The thinking was that TMS drift is the reason we are not fining repeatable offsets, and that by reverting at least things would be more repeatable from day to day.  The old offsets worked OK, giving us a recycling gain around 34 at 2 Watts and 24 at 50 Watts, although at 50 Watts we saw the CSOFT instability slowly growing.  We also see that at 40 Watts we can recover a recycling gain of 32 by using our old pop A offsets (0.4 pit, 0.2 yaw)
• We modified the a2l script so that we can run it while the SRM dither loop is on, and ran it.  (for now I saved the modified scripts with _LHO at the end of the name.)
• We have continued to have trouble with the CSOFT instability and tried to improve things by turning up the gain of the ISS 3rd loop by a factor of 10.  However, the third loop seems to have no effect on the instability tonight, although in the past it has clearly damped it. We weren't able to measure the open loop gain because each time we tried to measure we broke the lock, even with a fairly small excitation.
• We powered up with the dither lines on, and saw no evidence for spot motion on the test masses (consistent with what was seen in the past). 
• In our last two locks we powered up with dither lines on the PR optics and beamsplitter, and can see clear changes in the spot positions as we increase the power (power ups starting at 8:56:52 and 9:50:30 UTC), and we can see that that when we adjust offsets to improve the power recycling gain we are partially resotring the spots to their orgiginal positions before the power up.  We will work on calibrating the data, the attached screenshot shows uncalibrated spot positions for PRM in maroon, PR2 in orange, PR3 in red, and BS in taupe.

We have noticed that since we are going to higher powers, things are misalined after a lockloss and become realigned as they cool off.  We might want to account for this someday to save time.

WP 6122 h1psliss model change (and subsequent DAQ restart)

Keita, Peter, Patrick, Dave:

We installed Keita's PSL ISS model change on h1psl0. I also restarted the PMC model to see if it closed the shutter (it did) so now I have DAQ data on this problem.

We restarted the DAQ for the new ISS INI file. This also applied the FMCS changes (addition of Relative Humidity channels).

This will generate an alarm on pump level. 

Filling at 45% open on LLCV, past 100% full until I see a change in flow meter curve or until ~20 minutes go by (takes around 30 min. for LN2 to spew out the exhaust).

J. Kissel, J. Warner

As Jim brought the instrument up this morning, we were alarmed to see a forest of lines around 20 to 25 Hz. As they did not disappear or change height as we went through the lock acquisition sequence, as ASC loops turned on, noticed them in MICH and PRCL, found a whole bunch of ASC-ADS SDF differences, and I heard Shiela suggest that she might try an LLO scheme for dithering the alignment, I began to suspect that these lines were intentional.

Indeed, after poking around, I found the dither alignment overview screen and found several oscillators pushing out excitations at 
19.1, 19.7. 20.1. and 20.8 Hz in Pitch and 21.3. 21.9, 22.3, and 23.0 Hz in yaw, being sent to PR2, PR3, and the BS.

I confirmed that these lines actually make it to the SUS by gathering an ASD of the input control request at the bottom of PR2, PR3 and the BS indeed I see the same features in PR3 and BS (why not PR2?).

*phew!*

We'll leave these on, in case the plan was to just gather data with these lines present.

See attached ASD of input request to the SUS, a screen cap of the Dither Overview screen, and the corresponding DARM ASD.

Late entry from yesterday. 

The AC power for the Kepco high voltage supplies (provide ±430V to the LN ITM ESD Driver) were connected through the safety interface chassis D1400047. Interlock enables/disables the high voltage power supplies. The safety relay is controlled by the output of the Inficon guage installed on BSC7.

The positive high voltage supply was also replaced. Unit was found tripped and even after power cycing, would trip again every 10 minutes or so. One thing we noticed was the screen would lock up and then go blank.

Started Famis Task to check all the CPSs weekly.  This noise has not been seen since June3, aLog 27549. Will move FRS 5615 to pending and recommend closing.  Maybe power outage 6 June helped.

100mL of water was added to the Xtal chiller to bring the sight-tube level to MAX. Xtal flow is 20.1 l/min. Diode chiller was not in alarm and flow rate showed 31.5 l/min. FIlters showed no discoloration to note.

The front end pump diode temperatures were adjusted to increase the laser power.
  - D1 was 26.6 degC is now 26.4 degC
  - D2 was 24.6 degC is now 24.4 degC
  - D3 was 27.8 degC is now 27.5 degC
  - D4 unchanged
The temperature changes increased the output power by ~300 mW.
Increased the diode currents for the front end laser to bring the power back to where it should be.
  - D1/D2 was 45.5 A is now 46.0 A
  - D3/D4 was 47.5 A is now 49.5 A

    The net result is that the front end laser power increased by 1 W.  That helps to preserve the
injection locking bandwidth a trifle.

    The temperatures of the high power oscillator pump diodes was also adjusted.  A 4 W increase
was obtained.  The diode currents were not touched.

Observatory Mode taken from Unknown to Commissioning

Some recovery from Maintenance Thurs (Roll Modes and checks of violin modes).  Rest of the evening consisted of Commissioning work (Jeff

Worked on damping out Roll Modes of ITMx (with Sheila's tutorial).  Spent about ~30min (started at 4:58pm)

Received some Test Mass Coil WD Verbal Alarms (i.e. ETMX RMS ['LR'] WD has tripped).  And this was a first for me.  Kissel pointed me toward how to untrip these (Jeff said this WD is for the Test Mass penultimate masses (which is L2?).  For L2, the WD Trips are located on the right side of the SUS screen (RMS WD RESET).  To clear, put in a 1.0 for the UL & then take it back to 0.0.  This seems to take care of it for all the coils!  Kissel was concerned that these sort of WD trips could be a sign for violin modes ringing up.

SIDE NOTE:  The operator electric table apparently couldn't take my weight & failed.  Please do not use this table until it is repaired.

We had a couple locklosses when the ISS saturated, both with the third loop on and off.  We just increased the ref signal to -1.52 V to move the diffracted power to around 4%.  Was some setting incorect after a reboot this morning?  SDF indicated that everythind is OK. 

PT-140a (pirani) is off scale again, after more adjustments to pot this morning by Gerardo. It was working for a while today, reading in -4 Torr range and the CC was ON. I'm reopening FRS ticket 6061 so Richard et al can look at wiring.

Noticed that when I turn CC on the pirani reading drops from 1e-3 Torr to 5e-4 Torr.

Note that when we powered down PT-110a (on HAM6) we noticed a change in PT-140a. 

I was perusing the lsc model and noticed that it looked terrible. The reason was that the lsc/common/models/lsc.mdl file has been saved with matlab-2015b and looks very bad when viewed with matlab-2012b (please see attached screen shots).

Currently CDS has standardized on matlab-2012b for all front end model files. I checked all the H1 files and found we have three model files which have been saved with 2015b (lsc,mdl, h1isietmx.mdl and h1isietmy.mdl). Having a file written by different versions of matlab also makes 'svn diff' essentially worthless due to the large number of format differences.

I'll convert the 2015 formatted files back to 2012 format. Perhaps adopting a later version of matlab for CDS is a topic for discussion with a larger audience.

The left plot is the 2015-format file viewed with 2015b, the right plot is the same file viewed with 2012b.

Plot shows OSEM IN goes to zero, pitch goes to zero, but the COILOUT drive and voltmon remain essentially unchanged from before and after the event at 11:15UTC.

I cannot change OSEM values with alignment slider or by removing all drive from the coils.

Plot 2 shows all of the IMs and MC1 and MC3. 

IM4 Trans oscillates after the event, then is quiet.

I have already mentioned the possibility of a broken wire, to explain this event.

Running a Worden experiment:

-CP4 at 88% full
-Set LLCV to nominal in manual mode (41% open)
-Increase LLCV by 5% (43% open) and leave it at this value
-Monitor increase in fill
-Allow fill to exceed 100% and monitor exhaust flow meter (expect a sharp increase in flow when liquid starts to hit warm exhaust)
-After this sharp increase, reduce LLCV by 10% to below nominal (<41%)
-Hope that no LN2 reaches the flow meter this time (when flow approaches 100% I will monitor while sitting next to exhaust to be ready to open bypass exhaust valve and remove flow meter with LN2 gloves on)

**THIS WILL GENERATE CP4 ALARM ON PUMP LEVEL**

I swapped the oplev laser for the ETMy optical lever in order to address the problem noted by Sheila here.  The laser will need 4-6 hours to come to thermal equillibrium.

The SN of the new laser is 130-1.  This completes WP #6013.