This is an update of the DCPD cross correlated spectra. This time I have added the one from Livingston which was integrated over 1266 hours using the O1 data. High noise durations (e.g. LLO 23453) are excluded from the integration.

The fig and mat files are attached.

TITLE: 03/30 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Jim
SHIFT SUMMARY: Good day for locking.  Had the IFO as far as DC Readout by 16:30.  Then some QPD and other work took me down.  Since then, we have been back to locking consistently.
LOG:
15:16 Krishna and Michael to EY BRS work

15:41 Bubba driving inside of both arms checking tumbleweeds

16:05 Chandra pump cart work in diagonal

16:26 Fil to EX QPD work

16:27 Karen and Chris done in LVEA

16:40 John and Bubba to LVEA

16:58 John and Bubba out

17:42 Fil and Richard back

17:45 Fil and Ed to LVEA HAM3 cabling

18:08 Fil and Ed out

18:18 Ed to LVEA

18:50 Ed out

19:30 Fil to EX QPD

19:53 Fil done

19:54 Jeff B to both ends

20:11 DAQ restart

20:30 Jeff B back

20:36 Ed to LVEA

20:47 Bubba and Nicole to MY

(Tasked by Aidan)

We were curious of how the HWS sled power decrease over time so we know when to swap them out. Below I've attached plots of HWSX and HWSY sled power (corrected for gains) and input current. The start time is when we replaced the SLED (April 26, 2015 for YSLED and March 1, 2016 for XSLED). I only plotted the time when the SLEDs were turned on (displays in number of days). XSLED shows deteroration of ~2% per day and YSLED shows deterioration of ~1% per day (given 7mW to be 100%, I don't think we are shooting 7mW out though but the trend looks reasonable). YSLED power decreased slightly faster when the input current = 94 mA.

XSLED data can be found here and YSLED data can be found here. The column goes Time|Power (mW)|Current(mA). The script to fetch and plot data can be found in the same directory.

The fast decay in the beginning is a known problem.

Carlos, Dave, Aidan:

h1tcsey was upgraded from U10 to U14. This week Aidan and I were able to install all the packages needed for HWS operation. We have handed the system over to Aidan and the TCS group for commissioning of this system.

Install instructions are in the wiki:

https://lhocds.ligo-wa.caltech.edu/wiki/HWSServerInstall

A busy maintenance day.

ISI-HPI EY BRS model change WP5798

Hugh, Jeff:

The h1isietmy and h1hpietmy models were changed to use the newly installed BRS in EY, same as what was done at EX.

SEI End Station SUSPOINT and GND-STS transmission to OAF WP5799

Hugh, Jeff, Joe B, Dave:

The suspoint and gound STS channels were transmitted from the end station ISI models to the corner OAF model using an additional RFM channel per arm. The two channels were MUXed into a single RFM channel. The path is: both channels sent from h1isietm[x,y] to h1peme[x,y] via two Dolphin channels. The two channels are filtered and then mux'ed inside h1peme[x,y] and sent out via a single RFM channel. The OAF model demux'es the RFM into two channels, assuming a single cycle delay in getting the data.

SEI HAM SUSPOINT addition WP5796

Hugh, Jeff:

The suspoint code was added to all the HAM ISI models.

SUSAUX upgrades WP5804

Jeff, Betsy:

Latest susaux model changes made.

Guardian PSL node added WP5797

Jamie, TJ:

new node added. Still needs to be added to DAQ?

NAT router OS upgrade WP5800

Ryan, Carlos:

Upgraded lhocds nat router to latest version. Discovered some issues, old system was reverted. Will invesitgate offline.

Machine reboots for security patching

Carlos:

machines which required rebooting for OS patching were rebooted.

DAQ frame writer instability, move wiper from writer to solaris server

Dave, Jim:

On monday we moved the h1fw1 wiper from h1fw1 to h1ldasgw1, running hourly at 10 minutes in the  hour. Tuesday we did the same for h1fw0, running on the hour.

Accidental restarts

cast of many:

We had two accidental restarts.

Around 9am the timing slave on h1lsc0 IO Chassis was powered down. Initially we restarted all the models, but later in the day Evan reported bad ADC channels, we we then did a full computer+IOChassis power cycle in the afternoon.

Around 4pm the h1psl0 IO Chassis was accidentally glitched. We did a full computer+IOChassis power cycle to recover following our earlier LSC lesson learnt.

EX Beckhoff vacuum gauges moved from slow-controls to vac-controls

Richard, Dave, Patrick:

Patrick found the problem when we tried this last week, so this week the X4,5,6 BPG vacuum gauges were moved from their temporary slow-controls location to the final beckhoff VAC controls at EX.

The channel names were changed in the process. DAQ minute trends were changed to preserve old trend data (older archives still need moving).

DAQ Restart

Jim, Dave:

The DAQ was restarted several times over the day to support the above changes. We had two bad starts:

On one start all front ends resynced except for h1susaush56 which required a start_streamers, which fixed it.

On one start many frontends did not resync and required a start_streamers, during this h1psl0 went out of sync and many start_streamers did not fix it. We eventually did a second DAQ restart and all was good.

HAM 8:   8 mA  @ IP and 3.8e-6 Torr at turbo
HAM 9:   10 mA (no more red light) and 2.3e-6 Torr at turbo
HAM 11:  10 mA+ (still with red light) and 4e-6 Torr at turbo (pressure went up)

Related alogs: 25768, 25847

This is a belated log. Some people suggested studying correlation between the cross correlated spectrum and DARM residual. So I looked into that.

I conclude that there is no clear correlation between the noise floor (or band limited rms) of the cross spectrum around 153 Hz and DARM residual.

[DARM residual and band limited rms]

Here is a plot showing how they evolved as a function of time throughout O1.

As seen in the plot, I do not see a clear correlation between the two data. Note that the band limited rms is the one for a frequency range of [150 156] and is artificially scaled and offsetted to make the plot more readable.

[DARM residual is a strong function of seismicity and ISI blend configurations]

Looking at the plot shown above, one can notice that there are some periods where the residual is small and steady, and the others are large by a factor of a few. This seems to be related to seismicity and the ISI blend configurations. Here I give one example study about it.

I looked into one particular interesting time where the EX ISI blend configuration was switched from one to another without losing lock. This is Dec. 26 2015 7:00-ish UTC (24483). The zoomed version of the above plot is shown below.

The lock stretch started at around 4:00 UTC of Dec 26 and the blend configuration was switched at around 7:00 UTC without losing lock. When the EX ISI blend was switched, the DARM residual increased by a factor of two or so. This is simply because of an increase of the low frequency motion. I made two spectra of the DARM residual, one for the time before the blend was switched and the other for the time right after the blend was switched.

From the plot, it is clear that the low frequency motion below 0.4 Hz increased after the switch while the rest of the frequency contents remained unchanged. So this tells us that the fluctuation of DARM residual is a strong function of seismicity and ISI blend configurations. Although I have not looked into other days throughly, I am guessing that the fluctuation we see in the DARM residual is just a measure of a combination of seismicity and ISIs' blend configurations. We know that the blend configurations were switched many times during O1 in order to stably lock the interferometer against winds and micro seismic.

Jenne, Hang, Sheila, Keita, Evan

Tonight it seems like we made some progress, although we haven't powered up yet.

• TMS X QPD A seemed to have some kind of saturation of segment 1, which was causing our soft loops not to work well (ie to sometimes drag the X arm alignment way off).  reduced the analog whitening gain for all 4 TMS QPDs, which used to be 9 dB in full lock but is now 0 dB. 
• We were able to power up from 2 Watts to 8 Watts and see the oscialltion several times to check if configuration changes had any impact on our CSOFT oscillation. A list of things that had no impact:
  • turning off ITM optical lever damping (4:34:05 UTC)  (still off)
  • turned on 0.44 Hz notches in SOFT loops (4:47)
  • turned on a resG at 0.44 Hz in DARM (4:56) (reverted right away)
  • set A2L gains using A2L script (5:07 UTC) (reverted right away)
  • CHARD low gain (5:30 UTC)
•  Lastly, we used the alignment dither system, with all the A2L gains set to zero, and tuned the soft offsets to center the beams on the ETM actuation nodes. (the soft offsets don't have much of an impact on the ITM spot positions.)  For future reference, the demod phases we used for pit were -25 degrees, for yaw we used -40 for osc1, -30 for the rest.
• With these offsets we were able to power up to 12 Watts before seeing the oscialltion, where previously we had been seeing the oscillation at 8 Watts.  This was before we understood the problem with the QPD saturations, so the soft loops didn't really keep us centered on ETMX as we powered up.  We stopped for a while at 10 Watts, ran the A2L script to set gains, and did a little bit of work to update the X arm green QPD offsets. 
• We have a new guardian state ENGAGE_SRC_ASC, which will just be convient because we have been going back and forth between turning these loops off after DRMI and leaving them on.  It is not tested yet.

The first screenshot attached shows the symptom of the xarm soft loop not working, as we power up the optical levers move, and the loops work to bring the QPDs back to their starting points but bring the optical levers in the wrong direction, causing the green to become misalined.  The second screenshot shows the individual segments of the X arm QPDs durring this time.  The third screenshot shows a power up (to 20 Watts) towards the end of O1, with no evidence of saturation, despite almost twice the power on each segment.  The last screenshot shows the noise of each segment, the bottom panel is before reducing the whitening gain, the top panel is after (the A2L dither lines were on, that is the forest of lines around 20 Hz). Although it seems like we have more sensible signals coming from the QPDs with the lower whitening gain, something still doesn't quite add up when you compare the second and third screenshots. 

Keita, Sheila, Jenne, Evan, Hang

The mystery about AS 90 WFS may be (partially) due to the drift of dark offset.

We checked a time of today when IMC-MC2_TRANS_SUM was 0, and found that the output of a segment of AS 90 WFS was as large as ~100 cts when it was dark. As a comparison, the total sum of 4 segments at DC_readout was ~ 1000 cts. After corrected for it, the AS 90 WFS signal looked more reasonable.

We then checked the dark offset of the same WFS roughly days ago, and found that it drifted by ~ 100 ct (see, e.g., two seg1s in the attached plots). This large drift seemed make it not a very reliable sensor as the drift of dark offset was at least comparable to the signal we looked for. If we wanted to use it, we might have to check the offset frequently.

Krishna, Michael

This morning we stopped pumping on the BRS-2 to add a ~0.57 g washer to the top of the balance which shifted the COM up by ~10 microns. We then resumed pumping and remeasured the transfer function using the piezo stacks we installed yesterday. The attached plot shows the results of the measurements along with the model assuming d=0 microns and d=+/-1 microns. 

Plan for tomorrow:
1. Stop pumping with cart and switch to ion pump
2. Remove piezo stacks
3. Install thermal insulation

Vern, Fil, Nutsinee

WP#5085

From the rotation stage random walk study we found that CO2Y rotation stage is off by ~30 deg when it's not behaving properly. Today we did some more test to narrow down the source of the problem and attempted to fix the problem. Turns out swapping out the rotation stage isn't as straight forward as I first thought so we went for less complicated approaches.

First we went out to the Ethercat chassis and look at the CO2Y rotation stage signal with an oscillascope while running the random walk script. The signal looked fine (Vern has the data saved in a floppy disk).

Then we swapped the sensing and motor cables such that CO2X software controls CO2Y rotation stage and CO2Y software controls CO2X rotation stage. This time CO2Y rotation stage behaved nicely and CO2X jumped. Attachment 1 shows CO2Y requested angle vs. measured angle and the differences. The data took after cable swap is plotted in cyan. Attachment 2 shows the same thing for CO2X. The jumpy red plot is the CO2X rotation stage data took after the cable swap (controlled by CO2Y software). Attachment 3 is CO2 power plotted against the requested angles. We concluded that the problem must be related to the software.

We planned to replace two things in the chassis: the CO2Y interface card (D1300131) and the dual motor controller (EL7342). After swapping the cables back in place, we replaced the CO2Y interface card (only). We also found lose connections in many places inside the chassis while doing the work so next Tuesday that chassis gonna have to come down so Fil can take a closer look. Anyway, swapping the interface card seems to have made the problem worse. Both rotation stages are now very jumpy, they have trouble going to negative requsted angles, and the measured angle goes beyond +-90 degrees. We were able to put the both CO2 power back to where they were before we started our work this morning but I wouldn't commission them at this point. The work is to be continued.

18VDC power cables are in pplace and terminated in the corner station. The BS oplev power cable is not yet installed.

Flip flopping between the need to use FASTIMONs OR NOISEMONS for a variety of commissioning or DETCHAR reasons (but not being able to support both sets of channels) today we reverted a small portion of the work towards integrating the FASTIMONs into QUAD-land from alog 25329.  Today we put the NOISEMONs back into the BS and QUAD models, keeping their original data rates and made the FASTIMONS commissioning frames only.  This required restarts of the h1susauxb123, h1susauxex, and h1susauxey computers.

The SUS AUX Channel Monitor medms then had broken links which I partially fixed.  I fixed the readback channel, but the long colored bit thing associated with every one of these channels (holds the same info as the read back) is a pain in the whooo to change so will have to wait until I can regrow some patience.

We did a little bit of ASC work today.  

First, while Kiwamu was running a TCS test I started a script to automate phasing of the WFS.  It uses the lockin, first runs a servo to set the phase of the lockin demod, then servos to minimize some signal.  We have it set up right now to phase the refl WFS to minimize the PR2 pit signal in Q for both REFL 9 and 45, and to minimize the SRM pit signal in AS 36 Q.  There is some code for exciting DHARD, but we need to test amplitudes, phases and gains for this.  The current version of the script does its job although it is painfully slow, and is checked into the svn under asc/h1/scripts  THe resulting phases are in the attached screenshot. 

We saw that the instability in CHARD pit was becasue somehow the LP9 got turned on again, this is now off and CHARD seems fine.  

We tried powering up, were fine at 10 Watts.  We had an instability in PRC1 and PRC2 yaw at 13 Watts.  I reduced the Q on the complex zeros at 1.1 Hz for PRC2Y, which gives us slightly better phase and gain near the point where we seem to be unstable. Attached is a screenshot of the OLG measured with white noise at both 2 Watts and 10Watts, we might need to do a swept sign to get a good measurement around 1 Hz. 

After about 10 minutes at 12 Watts, we had the usual fluctuations in the recycling gain.  So the high bandwidth PRC2 loops haven't totally solved the problem. 

For the record, these are angle settings that give approximately good CO2 powers tonight, and the powers to aim for from Kiwamu's note:

We have twice had the rotation stage for CO2 Y go to an angle that was wrong by a lot (sending a few watts to the test mass for a few seconds).

I'm leaving the IFO locked at 10Watts. 

This is a quick summary of today's TCS joy. I ran another differential lensing test today. I went to the other side of the differential lensing (CO2X goes higher power).

The highest cavity pole was 352 Hz in this test.

• CO2 X 500 mW --> 700 mW --> 500 mW
• CO2 Y 230 mW --> 80 mW --> 230 mW

This time, I also took many measurements of the intensity and frequency noise couplings periodically throughout the test using Evan's automated measurement script (20470). I will analyze and post them later. The second attachment is trend of some relevant channels.