Alexa, Sheila

We have been unable to lock ALS COMM for more than about 5 minutes tonight, I'm not sure if this is because of high seismic, or for some other reason.  (The microseism is around (or just below) the 90th percentile, and we have convoys of trucks) We have made a few measurements of spectra, not with the WFS engaged.  The attached screen shot shows two spectra, the red trace was taken with a gain of 8dB on in 1 of the common mode board, the green trace with 19 dB.  We wanted to reproduce that the high gain loop really has lower noise, but keep dropping lock. 

The botom panel shows the coherence with the ISCT1 accelerometer that Robert moved onto the periscope today. 

J. Kissel, A. Pele, A. Staley

All HSTS and HSTS at both sites have incorrect M2 and M3 coil/magnet COILOUTF gain signs.

While once again banging our heads against the IMC crossover measurements against Alexa's discrepant ALS COMM model, we had one more epiphany regarding the SUS -- RESPECT THE PHASE. Her lowest frequency cross-over, the M1-M2 crossover, which should have a phase of -180 [deg], was measured to have a phase of 0 [deg], but otherwise the magnitude matches exquisitely. Then I remembered her mentioning a month ago that LLO had to account for an unknown minus sign on there lower stages of MC2 to get models to match measurements. Having just recently found an AOSEM vs. BOSEM COILOUTF gain sign bugs on the QUADs during the coil balancing, it occurred to me to check that the M2 and M3 stages of the MC2 matched the PUM stage of a QUAD. They did not, and are indeed incorrect. BIFF!

Worried that it was a systematic flaw copied and pasted everywhere (and because green team need mode cleaner, but not PRM), I checked PRM. Also incorrect. To confirm that that sign orientation *is* in correct, we drove a DC offset on the lower stages of PRM, and indeed, a +L requested drive moves the suspension in -L (as measured by the OSEM sensors). I asked Arnaud to quickly plot the phase of the acceptance measurements that he had for one of these suspensions. ZLONK! +180 [deg] measured phase at DC, where we should expect (from any suspension on the planet) 0 [deg] phase at DC.

Sad about this, I then modified the acceptance measurement scripts to plot the phase of a random smattering all of the M2 and M3 acceptance measurements that have been taken of all HSTS at both sites. All have a phase of +180 [deg] -- see attached. POWIE!

The reason for the flaw in magnet compensating gains? AOSEMs and BOSEMs have coils wound in exactly opposite direction. So a positive current sent to a BOSEM coil will result in magnetic fields opposite in direction than the AOSEM coil. We realized this halfway through defining all of our suspensions' lower stage magnet signs, as is reflected by the poor quality of information in our sign convention documentation, T1200015, specifically the Cheat Sheet, where it shows a table of COILOUTF gains for "Any 4 OSEM Stage" as
    UL   -
    LL   +
    UR   +
    LR   -
which is the current sign distribution on the M2 and M3 stages for HSTSs. However, this table was created / determined assuming a BOSEM winding. You'll notice that the difference between -v2 and -v3 is "adding a AOSEM vs. BOSEM push/pull table," and the (unfinished!) statement that "AOSEM and BOSEM coils are wound exactly opposite in direct[[ion]]." CLANK-EST!

Naturally, because the HLTS EPICs values began as a copy-and-paste of the HSTS, any HLTS has this same flaw of its lower stages, but we haven't used them enough to notice.

Conclusions:
- All HSTS and HSTS at both sites have incorrect M2 and M3 coil/magnet COILOUTF gain signs. That's MC1, MC2, MC3, PRM, PR2, PR3, SR3, SR2, and SRM.

There signs should be:
    UL   +
    LL   -
    UR   -
    LR   +

- I blame myself.

- I clearly need to create a version 4 of T1200015.

- Of course this affects all IFO loops that use the HSTS, so I have not and will not change the signs unless I have whomever designed the ISC loops sitting next to me.

- Hanford Fire Maintenance fixing hydrant 1 by the woodshop

- Jim and Cyrus at MY working on PEM card.

- Dave B. two DAQ reboots today.

- Jeff B. and Andres R. at HAM4

- Robert S. installing accelerometers on ISCT1L

- Apollo installing  both doors on HAM4 with 4 bolts

- CDS implementing LSC and ASC model changes

- SUS doing transfer functions at EY

- Patrick T. doing a CONLOG update

- Karen at EY to clean

Until the guardian installation, I've been asked to write a quick procedure on how to turn back the BSC-ISIs on after a trip.

Right now, the best configuration for BS, ITMX, ITMY and ETMX is the same: lvl3 controller on ST1 and ST2, Tcrappy blend filters on ST1 and ST2. No sensor correction.

- Reset the watchdogs

- Check that HEPI position loops are still on

- Open the ST1 CART BIAS screen and click on Reset CPS offset then Store target offsets

- Open the commands screen and click on !Isolate <CHAMBER> lvl3

- A black xterm window will show up. While this pop-up window is there, don't touch anything.

- The isolation loops are now on. Next step is to switch to the good blend filters. Wait for the T240 signals to go down! The overview T240 indicator has to be ALL GREEN before doing anything.

- When you think the platform has settled down, open ST1 BLEND screen -> SWITCH ALL and select Tcrappy.

- If this process makes the ISI trips, that means you haven't waited long enough. Restart the all process. A trick that could work is to start switching the vertical blend filters (Z, RX and RY) first, then the horizontal ones (X, Y, RZ).

- Repeat the same process with ST2 BLEND.

Remember that we are dealing with seismic signal and very low frequency instruments. Be patient!

Andres & Jeff 

   Using a 3 axis translation stage on an optics post (see photos) we glued a new magnet/dumbbell assembly to the UR side of the SR3 optic, to replace the one that was knocked off on Monday. The process is straight forward and was completed in a couple of hours.
 
Procedure: 
1) Lock the Intermediate Mass in its level hanging position; then lock the Optic in its level hanging position.  
2) Adjust the placement  and X, Y, Z location of the 3 axis translation setup so the magnet flag holder is aligned on top of the ring of glue left from the original magnet/dumbbell assembly. 
3) Lock the Z and Y axis stages of the 3 axis translation setup in place so they cannot shift.
4) Retract the X axis stage as far as it can go to pull back the magnet flag holder away from the Optic face.
5) Using Acetone and Alpha swabs carefully clean the old glue from the face of the Optic. It helps to hold an Acetone soaked swab against the glue spot for several minutes to soften the old EP-30. Then with a second swab gently rub the glue spot. If the glue does not start to come off hold the Acetone swab against the glue spot for a few more minutes. 
6) Repeat the wetting and swabbing process until all the old EP-30 has been removed. 
7) Mount a new magnet/dumbbell assembly into the flag holder and apply a dab of EP-30 to the dumbbell. 
8) Slowly turn in the X axis stage until the dumbbell makes contact with the face of the Optic. 
9) Lock the X axis stage so it cannot shift while the glue dries.           

Jonathan Hanks, Jim Batch, David Barker

Reconfigured the badger.ligo-wa.caltech.edu web server to no longer accept http access using a common login.  Replaced with https LIGO.ORG authenticated service, which displays the Jenkins service running on x1boot.  Existing users may notice cached links to http pages need to recache as https 

Dave B., Jim B., Patrick T.

WP 4487

This was done primarily to match what Livingston is running. It adds:

1.1.0 -> 1.2.0
1. A reduced rate on the keep alive updates
2. A minor bug fix in the printing of startup messages

1.2.0 -> 1.3.0
1. A cron job to check for and mail information on frequently changing channels
2. A javascript datetime picker to the webpage
3. A link to the bugzilla for conlog to the webpage
4. Abbreviations for the timezone in the query results

Note that the code was restarted to run 1.3.0 before the channel list updates reported today by Dave.

There are still some configuration differences with Livingston that need to be worked out, but we are now closer.

   I monitored the dust counts during the installation of the HAM4 North & South doors. In general the particle counts under the cleanroom area were 0. Occasionally there were 0.3µ counts of 1 to 3 particles per 20 second sample time. I saw very few counts for larger particles.
 
   During the actual door installation dust counts were in the 1 to 5 particles per 20 second sample time. Many times during the operation the counts were 0. The highest counts on the North side were in the 75-80 0.3µ particles per 20 seconds sample time, during the removal of the two soft covers. The highest particle counts on the South side were in the 70-77 0.3µ particles per 20 second sample time, while the flange was being wiped down with alcohol. In both of these cases the counts returned to the 0 to 3 count range, in a few minutes.      

New cart bias screens have been installed for the BSC-ISIs and the HAM-ISIs.

The goal of this update is to make the cart bias clearer to non-SEI commssioners. Let us know if it doesn't and we'll take in account your remarks.

Patrick and Dave

following our instuctions in the wiki page https://lhocds.ligo-wa.caltech.edu/wiki/ConlogChannelConfiguration as a test we regenerated the conlog channel list after the latest Beckhoff autoBurt.req were added and new models installed.

539 channels inserted

197 channels removed

+342 nett gain of channels

I have added h1pemmy to the CDS overview MEDM screens. It is also added to the DAQ configuration files, which will be impemented on the next DAQ restart.

Cyrus, Jim, Dave.

The h1pemmy front-end, I/O chassis, and AA chassis have been installed to collect seismic data from the seismometer installed at Mid Y.  This equipment is installed in the equipment racks in the VEA, and uses DC power from the DC power supply rack also in the VEA.

1PPS timing is supplied directly to the I/O chassis from the master fan-out in the MSR, so no IRIG-B is present.  This makes starting the IOP model a bit tricky as it gets it's initial time from the computer system clock.  More than one try may be needed to get the GPS time sync'd with other models.

The computer network connections are from the CDS switches at End-Y.

The h1pemmy model is copied from h1pemmx, with the vault section removed.  

The seismometer is connected to channels 1, 2, and 3 of the AA chassis, but verification of which channel corresponds to X, Y, and Z is left to our PEM expert.

Arnaud is launching our last* set of time-critical TF's on the ETMy which will tell us if we are clear to put the spool on tomorrow or not.  Please don't do anything at EY to disturb any of the watchdogs set on the chamber equipment (HEPI/ISI/SUS/TMS).  Normal foot traffic, ISC table work, cleaning, etc OK.  Thanks!

After Jim finished up some SEI checkouts and Mitch some ACB hardware swaps at WBSC10, Travis, Jason and I put the final touches on the pitch alignment.  (Recall it was out of the pitch tol yesterday after we removed the First Contact sheet on the HR surface.  The ISI is unlocked, and so is the ETMy and TMSy.

While in-chamber, we observed more particulate on places that we had previously cleaned.  So, I took more PCL samples for Kate near the purge air port (to look for migration) and on a repeat place from a prior sample.  For the most part, "we" have been cleaning the floor and large easy to get to surfaces in-chamber every day.  I also went upstairs and clened the entire surface of the walking plates which have had little attention, hoping to limit what is getting stirred up and dumped in from above.  I left a box of wipes there for SEI to keep up better mainenance there from now on.  ;) 

I left a witness plate and a 1" optic in the tube under the ACB (between the purge and the chamber optics) for Kate to do further studies on.

We'll keep hunting.

Several of the TMS Cable connectors are missing screws to attach to the vacuum feedthru plugs.  Have discussed with Keita and because these connectors are a tight fit into the feedthrus as they are, we will not worry about installing these screws in the connectors.

I re-measured BS and PRM actuation transfer functions in PRY configuration after plant inversion done on Mar 5 (see alog #10559).
It seems like we succeeded in BS and PRM balancing within ~8 % and MICH to PRCL coupling is expected to be supressed by factor of ~4, compared with using only BS as an actuator.
For the sensing matrix measurment, the effect of residual MICH to PRCL coupling gives ~6 % error for MICH to REFL45Q element and ~16000 % error for MICH to REFL45I element.

[Motivation]
Before measuring the PRMI sensing matrix, we wanted to estimate how good output matrix diagonalization is.


[Method]
1. Lock PRY and measure open loop transfer function. Compare it with the model to derive optical gain.

2. Measure actuator transfer function of BS and PRM from ISCINF to REFLAIR_RF45_I_ERR in PRY (using the same template used in alog #10450). Calibrate these TFs into m/counts with the optical gain derived in step 1.

3. Closed loop correct TFs measured in step 2. TFs should look like 1/f^2 at 1-300 Hz (see comments on alog #10450). Since output matrix for MICH in PRMI are set to (BS,PRM)=(1,-0.5), these TFs should be equal (see alog #10559 and table below).

-table of actuation efficiency (optic motion to interferometer length change in m/m)-
      PRY      PRCL      MICH
BS    sqrt(2)  1/sqrt(2) sqrt(2)
PRM   1        1         0

4. Calculate expected actuator TFs for MICH to PRCL coupling using the measured TFs. BS ISCINF to PRC length change will be half as that of PRY. BS-0.5*PRM gives the residual MICH to PRCL coupling.


[Result]
1. OLTF_PRCL_1078572000.png: Openloop transfer function of PRY lock. By comparing with the model, this gives PRY optical gain of 1.8 W/m. So, the calibration factor for REFLAIR_RF45_I_ERR in PRY is 4.7e11 counts/m. Note that this calibration factor includes losses in the PD signal chain (e.g. loss from long cable). Also, note that PRM suspension model was 30 % off from the measurement (see #10482; measurement = 0.77 * SUS model). This correction factor is included in the model to derive the optical gain.

2. BSandPRMact_PRY.png: Measured actuator transfer functions for BS and PRM in PRY. x marks show raw measured TFs and dots show closed loop corrected ones. After closed loop correction, actuator TFs look like they follow 1/f^2. From the fit, BS actuator TF is 1.79e12 Hz^2/f^2 m/counts and PRM actuator TF is 1.93e12 Hz^2/f^2 m/counts for PRY. Considering the error bar from coherence and cavity build up fluctuation during the measurement, this 8% difference between BS and PRM is significant (error bars in TF magnitude are derived using the formula in alog #10506). We have done the balancing with the precision of ~10%, so this difference is reasonable.

3. BSandPRMact_MICH2PRCL.png: Estimated MICH to PRCL coupling from actuator diagonalization. Blue dots show BS ISCINF to PRC length change and red dots show BS and PRM combined actuator to PRC length change. Fitted lines show that MICH to PRCL coupling is expected to be supressed by factor of ~4 by actuator balancing. We can improve this supression ratio a little bit by changing the gain balancing between BS and PRM by 8%, but it's not easy to improve more and prove we did more.


[Is this enough?]
This means that our MICH actuator (BS - 0.5*PRM) changes MICH length by 1.79e12 Hz^2/f^2 m/counts and PRC length by 2.06e11 Hz^2/f^2 m/counts. According to Optickle simulation in LIGO-T1300328, sensing matrix for PRMI sideband is

            PRCL    MICH
REFL 45I    3.4e6   2.5e3
REFL 45Q    6.4e4   1.3e5  W/m

So, the estimated effect of residual MICH to PRCL coupling to the sensing matrix measurement is;

MICH to REFL45Q element:   6 % error (= 6.4e4/1.3e5/(1.79e12/2.06e11) )
MICH to REFL45I element: 16000 % error (= 3.4e6/2.5e3/(1.79e12/2.06e11) )

If we ignore MICH to REFL45I element, which is hard to measure anyway, I think this is acceptable.


[Next]
 - Update gain balancing factor between PRM and BS from 1/16 to 1/14.7 (FM5 in H1:SUS-BS_M3_LOCK_L)
 - Update IQ demod phase in H1:LSC-REFLAIR_A_RF45_PHASE_R to minimize PRCL to MICH coupling
 - Measure sensing matrix in PRMI

Alexa, Sheila

Tonight we decided to try to charachterize the coupling of alingment fluctuations to the error between the arm resonance and the ALS COMM lock point. We did this using the normalized PDH error signal.  The frequency dependence of this spectrum is unclear- if we were staying on resonance we would just have the cavity pole, but the transfer function of the transmitted light will change as we move over the resonance.  So to make a good calibration we need to lock well enough to stay on resonance.  (This is why we have been trying the AO the last few nights).  For tonight we concentrated on low frequency noise that is dominating our RMS, where the frqeuency dependence won't matter anyway.

We put a 1 Hz excitation onto ETMX pitch, making it large enough to see the second harmonic.  We measured the spectrum of our REFL_DC_BIAS error signal when COMM was locked, and the op lev spectrum with and without the excitations.  The attached screenshot shows the spectrum with and without the excitation.

Measuring the peaks due to the excitation we estimated the coupling coefficient with excitations of 2 different amplitudes, 1.7kHz/urad and 1.5kHz/urad.  We also can esitmate the quadratic coupling from this data, we got 159Hz/(urad)^2 and 170 Hz/(urad)^2

Attached is a plot of linear and quadratic projections based on the Oplev data (up to 4Hz) into the REFL_DC_BIAS path.  It can explain all the noise around the pitch resonance (which is most of the RMS), but not elsewhere.  We had wondered if the coupling was nonlinear and some of our unexplained noise from 1 Hz-50Hz  (or below 0.3Hz) was upconverted angular fluctuations.  Our measurement suggests that this is not the case. 

We were planning to repeat this measurement for ITMX, but so far we have been prevented by and earthquake. 

After SUS team was gone, we went in the BSC10 to check a potential rubbing issue that has been bothering SEI.

After backing off all EQ stops and making sure that the top mass is free, we've found that the top mass had ROLL tilt, and somewhat smaller PIT. We don't know where this came from, but in my experience TMS angle changes after transporting to the chamber.

We corrected the roll and PIT by moving top balance masses, roughly centered all BOSEMs (the only one that was left untouched is RT) and left it damped.