To get bigger plots in dataviewer (i.e. getting the plot window to auto-scale) for both playback and 'real-time' plots, you can now just set up an option in your GRACE environment:

1) In your user directory make a directory called .grace:      mkdir .grace

2) Change to that directory:                                   cd .grace

3) Copy my gracerc file into your directory:                   cp /ligo/home/rana.adhikari/.grace/gracerc.user .

Now, when you restart dataviewer, you will have autoscaling.

BTW, this is described somewhat in CDS Bugzilla #377 from Tobin Fricke, Jim Batch, & Keith Thorne.

Completed the BSC file modifications today like the HAM-ISI yesterday and HEPIs last Thursday.  Now all SEIs are monitored by SDF with Guardian doing the rest.  There remain red issues (5 platforms) I did not clear to remind us of ongoing questions & issues to address.

Summary:

QE and transimpedance combined for Baffle PD1 and PD4 on all ITMs and ETMs agree with each other within 10%. In the table below, QE/transimpedance combined for each PD is normalized such that the average of all diodes becomes 1.

I haven't done any error analysis, but the biggest error should be the systematic in ITM-ETM comparison that was introduced by an assumption that IR mode matching is perfect.

PD1-PD4 comparison on the same baffle (e.g. ETMX PD1 and PD4) should be quite good.

Details:

This is yet another baffle health check.

The other day I used some short time available to misalign TMS and steer MMT3 to point IR beam on ETM baffle PD4, first on  ETMX and then on ETMY. This could be used to make ETMX(PD4)/ETMY(PD4) comparison, assuming that the IR straight shot beam size is the same on ETMX and ETMY.

Then I proceeded to align MMT3, align ETMs to point the beam to PD4 on ITM baffles. Since ETM reflectivity is basically 1, and since the mode matching cannot be as bad as green, we can use these measurements combined with nominal IR beam size to make ETM(PD4)/ITM(PD4) comparison.

Also, when people do initial alignment they are basically doing PD1/PD4 comparison on a single baffle using green beam. (You cannot make comparison across different baffles using green because of the beam size difference described in my previous alog.)

So, stitching all these together, if we believe that the QE variation of diodes for green is the same as that for IR, we can map out the QE/transimpedance combined for all baffle diodes.

In the table below of the raw data, photo current in mA for straight shot measurements of green on PD1 and PD4 as well as IR on PD4 on all arm cavity baffles are shown.

Green data can be used to make PD1/PD4 ratio on each of the optics.

IR ETM data is used to make PD4 ETMX/ETMY ratio.

IR ITM data, combined with the nominal IR beam radius on ITM and ETM (53.4 and 63.5 mm, respectively), is used to make PD4 ETMX/ITMX and ETMY/ITMY ratio.

After some math we get the table at the top of this entry.

06:45 Karen into the LVEA

07:00 Cris into the LVEA

08:00 set OIB to 'Commissioning'

08:05 unlocked DRMI to start practicing locking Green light to arms (ALS) No luck. Later learned the proper way to unlock DRMI. Thanks Kiwamu

08:30 Morning meeting

08:45 Started working with Kiwamu on getting my first arm locks. SUCCESS!

09:09 Betsy and Mitch to W bay

09:22 Jeff B to LVEA

09:29 Mike L into LVEA

09:30 Jeff B out of LVEA

09:49 Mike L out of LVEA

09:52 McCarthy to EX

10:54 Betsy and MItch out of LVEA

10:55 Caterers on site

11:03 McCarthy back from EX

11:07 Fil to MY

11:43 Fill back from MY

12:15 Vanessa to MY

12:24 S&K Electricians to EY

The temporary barrier originally installed for the DCS construction has been removed. Mechanical is 98% complete with remaining items being plenum grills and dampers, start up of the HVAC system by a factory rep, installation of cable trays and some touch up painting. Electrical is on the order of 70% complete. 

Like the quad model scripts (LHO 16126), I updated the generate_Triple_Model_Production.m and generate_Double_Model_Production.m functions so that you can specify a foton filter for the top mass damping loops.

The generate scripts is in

.../SusSVN/sus/trunk/Common/MatlabTools/TripleModel_Production

and

.../SusSVN/sus/trunk/Common/MatlabTools/TripleModel_Production

If youhaven't done so in the past week, you will also need to svn up

.../SusSVN/sus/trunk/Common/MatlabTools

since this is where the foton file reading functions are located (imported from the SeiSVN)

You can still specify the usual .mat struct file as before. The generate script looks for the .txt extension to determine if you are sending it a foton file.

Here is an example of how to make a model with damping filters read from foton:

hsts_model = generate_Triple_Model_Production(frequency_vector_for_plots, 'hstsopt_metal', [], 0, 1, '/opt/rtcds/lho/h1/chans/H1SUSMC1.txt')

IMPORTANT: The foton file does not know which filter modules are engaged. This information is coded into the function with a variable called medm_engaged_modules, which must be updated at the time of running the script. The script will output to the command line which modules are being used for each filter, and where to change in case you forget. For a variety of reasons I thought it more convenient from a user-point-of-view to have this coded into the function rather than as another input to the function, however this could be modified. This is the same in the quad script.

These functions have more instructions commented into their headers.

Just have the single sus scripts to go.

Summary:

Green straight shot beam size on ITMX is a factor of 0.87 of nominal (i.e. too small) while ITMY a factor of 1.2 too large.

The beam radius ratio is (X/Y)=0.72, which makes the ITMX baffle PD output current to be a factor of 2 larger than that of Y when you hit these PDs using a straight shot beam.

There used to be a factor of 2 to 2.5 unexplained difference between the photocurrent in ITMX and ITMY baffle diodes during initial green alignment, but the beam size explains a factor of 2, so the remaining factor is about 1.2 or so, which I don't care for now.

Background:

This is one of those health check type stuff. Baffle PDs could be used for scattering measurement but the health of some of those PDs were in question.

One of the suspicions came from the fact that, when looking at green straight shot beam during full initial alignment, PD current from X arm baffle is much larger than Y arm. A part of it comes from the laser power (there's about a factor of 2 or so difference) but the baffle PD current is a factor of 4 to 5-ish different, so there always was a factor of 2 to 2.5 unexplained.

Details:

I first used dither align script to point the TMS beam to PD1 and then PD4 of the ITM baffle. Since the horizontal distance between PD1 and PD4 is 11.3", the script allows us to calibrate TMS alignment slider.

Immediately after the script finished, I pointed the beam to PD4 center, move TMS in YAW in one direction by more than the beam radius,  and ran another script to move TMS in YAW, wait and measure PD4 current.

Attached is the YAW scan data (circles and crosses) as well as the fit to Gaussian profile assuming the same radius in PIT and YAW:

current = ofst+ A * 2/pi/w^2 * exp(-2*(X-X0)^2/w^2)

where w is the beam radius and A is an overall factor.

The last column in the above table shows QPDA_SUM+QPDB_SUM. If everything makes sense, and if the beam was at the same height as the PD center during the scan, QPD_SUM ratio should agree with A ratio, but apparently it doesn't at 20%-ish level. This is good enough because the suspicion was that there was something grossly wrong about the baffle PDs.

BTW we can do the same thing for IR beam, scanning MMT3, to assess the IR matching to the arms if we want to (or better yet, do the spiral scan to see both PIT and YAW).

Looks like lock was from about 9:14 UTC to 16:09 UTC. For posterity.

http://earthquake.usgs.gov/earthquakes/eventpage/nc72387946

Ground velocity exceeds 20 μm/s from 0.03 Hz to 0.1 Hz. IMC MC2 transmission is noticeably wobbly.

Added 2 channels and removed 788.

Work Permit review.

SEI - continuing work on SDF system for BSC ISI. HEPI pump servo is ongoing tinvestigation. Maybe Jeff will run some TFs looking at 1Hz to 10Hz at some point today.

SUS - no big news. Thomas will ressurect the Drift Monitor this week sometime.

ISC/Commish - taking small steps in the positivedirection. Had a rather lengthy DRMI lock last night beginning ~01:30.

3IFO - no activities in LVEA. All activities across the street.

Facilities - Beam Tube cleaning is ongoing. Gutter work is don at LSB. Crew has moved to VPW.

CDS - variac installation at End station for Heater. Work in HAM6 area on Fast Shutter. R Abbott will be coming to work with this.

Gary will be moving ISS arrays and using the large airlock door in the LVEA

model restarts logged for Tue 27/Jan/2015
2015_01_27 01:43 h1fw0
2015_01_27 03:04 h1fw1
2015_01_27 08:57 h1iscex
2015_01_27 09:03 h1iscey
2015_01_27 09:18 h1isiham6
2015_01_27 16:32 h1fw1
2015_01_27 23:42 h1fw0

4 unexpected restarts. Light maintenance day, minor model changes for End ISCs and ISIHAM6 which did not require DAQ restart. Conlog frequently changing channels list attached.

I opened the gap between the bundle of copper pipes that were again rubbing on the ITMy optical lever TX pier causing the 10min-ish sawtooth signal. This is a temporary fix, but is more stable than the first time we saw this. It is in the planning to reroute the pipes and fix other similar issues with other oplvrs.
Keita ran a new scan verifying the fix.

The OIB was set to commissioning upon my arrival for shift at 08:00. DRMI was still locked. I'm going to try my hand at locking the arm(s) as no one is here working yet.

I touched up the RM suspension controls today. RM1 had been tripping its watchdog often during the engagement of the scripts which use the RMs to center the beams on the REFL WFS.

1. Moved the RLP11 low pass filter into the damping filter banks. This is less aggressive than the 5 Hz Cheby low pass that was there and allows for more stable recovery from saturations. The damping gains were checked; seems reasonable.
2. Turned on the LIMIT for the damping filter banks at 1000 counts. This is similar to what I did with the IM mirrors recently.
3. With the DRMI aligned, I adjusted the alignment biases to center the beam on the REFL_A and REFL_B WFS.

Now, when the scripts turn these on the RMs do not trip and the beams are centered.

We have left the DRMI locked (on 1f), Guardian undisturbed starting around 1:13 AM for seismic performance evaluation.

Sheila, Evan, Rana, Eli, Kiwamu, Alexa

Today we were able to reduce the CARM offset from 800pm to 100pm. We made three major changes to acheive such an offset.

1. We noticed that the sqrt(TRX+TRY) counts into the CM board was only about 100 pk-pk. We increased this to about 800pk-pk by reallocating some gain. We decreased the LSC-REFL_SERVO_IN1_GAIN from 0dB to -16dB, and increased the LSC-REFLBIAS_GAIN from 8 to 50.4.
2. We added a z20:p40 to REFLBIAS in order to get more phase and push the UGF of TR CARM from 200 Hz to 150 Hz. This filter is only engaged after we have already turned off ALS COMM, at which point we do not need to compensate for the COMM PLL VCO.
3.  We noticed that ASAIR_RF45_Q was rather noisy as we were reducing the CARM offset. We added an integrator FM2 (z2:p0) to ALS DIFF to reduce low frequency noise. This helped make TR CARM more stable.

Transition Process from 800 pm to 400pm

To start,

• LSC-TR_CARM FM1(2pm), FM9(z35:p1k^2) ON
• LSC-TR_CARM_OFFSET = -0.5
• LSC-REFLBIAS FM9 (z40:p1.6), FM3 (z40:p1) ON, GAIN 50.4
• LSC-REFL_SERVO_IN1 GAIN -16dB
• ALS-C_REFL_DC_BIAS GAIN 28
• TRAMPs at ~13 s

With some TR buildup (approximately 1ct on LSC-X/Y_TR_A_LF_OUT),

• LSC-REFLBIAS FM6 (z1:p0), FM4(z1:p40) ON, GAIN 28.0
• Ramp down LSC-REFL_SERVO_IN2 Gain from 16dB to -32dB then turn off ALS-COMM

With CARM on sqrt(TRX+TRY),

• LSC-REFLBIAS FM10(z20:p40) ON, GAIN 28 at -0.5 cts offset (Note: the gaurdian does up to this point)
• LSC-REFLBIAS GAIN 39 at -1.0 cts offset

Transition Process from 400pm to 100pm

With all the settings as above, we bring the CARM offset to -3.2 (or ~150pm). At this point we transitioned the in-air TR PDs to the IR TR QPD_Bs.  For reference, ASC-X/Y_TR_B_POW_NORM =1,1  and LSC-TR_X/Y_QPD_B_SUM_GAIN = 0.222, 0.175 respectively. Also, the QPD NSUM was about 400cts here. We continued to reduce the CARM offset to -4.5 cts (or ~80pm). At first,t the ASAIR_RF45_Q looked like a decent signal and responded well to a DIFF offset change. We turned on a servo for about 1.5min to ensure ASAIR was around zero (z servo -r LSC-ASAIR_A_RF45_Q_NORM_MON -g -11111 ALS-C_DIFF_PLL_CTRL_OFFSET).  We measured ASAIR_RF45_Q/DARM_IN1 = 3e7 (at this point DARM_IN1 is just ALS DIFF signal). Note: we added a -160dB FM10 filter in LSC-ASAIR_A_RF45. Then the PD_DOF_MATRIX for ASAIR_RF45_Q is 3.3. So far, we were able to transition from ALS DIFF to RF DARM 50% of the way, and then we broke the lock. We started to reconsider whether we were actually in the linear range for RF DARM. Maybe we should be using AS45Q/SQRT(TRX) at this point? This requires a model change; however, this is already impleneted in the l1lsc.mdl that is in the SVN, so we could just copy that.

A little more ...

The farthest CARM offset we reached was -7 cts or ~60pm on sqrt(TRX+TRY) with the QPDs controlling CARM and ALS DIFF for DARM. Here we had 26 x single arm power, and REFL DC dropped from 80mW to ~75mW.

J. Kissel, B. Lantz, H. Radkins

Hugh and I, with the remote advice from Brian, have been investigating the coupling between HEPI differential pressure noise and HEPI platform motion (see preliminary studies in LHO aLOGs 16231 and 16309). In summary, the coupling is smattered between every chambers DOFs, limiting the performance between 0.02 and 2 [Hz]. There's no pattern as to how this coupling occurs except that the coherence for a given DOF happens in a similar frequency band in all chambers. All chambers show differential pressure moderate coherence to HP, but we're still working on estimating the transfer functions between this "pringle" mode and any translations / rotations to assess this impact. Further, we still have set up any successful long stretches of IFO / WFS data for the DRMI, so this pressure noise' impact can't yet be assessed. However, for now, I continue under the assumption that *any* low frequency improvement, especially to RZ / YAW, will improve the relative angular fluctuations of the IFO and stabilize optical gains, etc.

Hugh has already revealed the punchline: this morning's pump-servo OFF data shows that the problem is entirely because is of noise on differential pressure sensor. I'll attach a comment with complete set of plots for proof in a bit.

Further discussion on the noise as it stands with the pump servo (i.e. ON), based on the attached plots, which include

• ASDs of all Cartesian (plus pringle) DOFs' L4Cs -- out-of-loop witness sensors -- compared against the differential pressure and the expected sensor noise**,
• Coherence between all Cartesian (plus pringle) DOFs and the differential pressure,
• ASDs and RMS of Colocated Actuator Drive signals, compared against the differential pressure and the 2 [hr] mean, DC value of each signal,

is below. I post all of these discussion points for future reference and design considerations to show how nastily and diversely imposing sensor noise on the pump servo imposes the platform motion. But mostly, because I sorted through a TON of data and plots to make these conclusions, before we knew the source of the problem.

** For the HEPI L4C ASDs, I plot the *raw* sensor noise because (a) I'm trying to cram as much information on as few plots as possible, and (b) the scale factors for both the IPS and L4Cs are the same for each DOF, and are all between 0.3 and 1.1, so the estimation estimation is off by at most a factor of three. Mostly it's there just to guide the eye, as a primitive noise budget.

(1) Krishna (before coherence between all DOFs and chambers was fully flushed out), suspected that because we now run Z sensor correction is on HEPI, the extra drive force meant excess pressure noise coupling. However, compared to 23e3 [ct_{rms}] range, the Vertical RMS of 5 [ct_{rms}] is peanuts. Further discussion of DC / mean requested drive is below.

(2) Brian suspected that the passive filtering system, the accumulating bladders might not be operating at their nominal air pressure. However, pump 8's (out of 12 for the corner) bladder pressure was checked last week, and was within spec. There're still lots lots to check, but Hugh suspects they're also OK.

(3) I suspect the PID controller for the servo is likely not well-tuned for new differential pressure sensing, suggesting we need to remeasure plant (which could mean significant down time for the IFO). There's been some discussion offline in the SEI group as to how we should systematically characterize the pump servo plant, given there's no "fast" excitation point in the pump servo make a tranditional frequency-response transfer function difficult (see SEI aLOGs 684 and 686). For now, we suspect we can do a sufficient characterization with simple steps using the existing EPICs infrastructure. Characterization to-date (though very early on in aLIGO) was also made by step response (see E1100508), but the assumptions about the plant don't seem sound in retrospect, and were done when the pressure was still on an absolute "single ended" readback.

- Brian's "Allowable Pump Servo Noise" defined in T1100198, but contains a LOT of assumptions. One of which is that the open loop gain transfer function of the feed back loops is "100 at low frequency." As such, Brian suggests, if the HEPI feedback loops are gain limited, try adding some boost at these frequencies to suppress the noise. However, I argue, with Hugh's recent redesign of the controller (see LHO aLOG 15308, the relevant attachment re-attached here), RZ Loops for example have *plenty* of gain, upwards of 3000 - 4000 at 0.1 [Hz], typically asymptoting to a few million a DC. This is far more than Brian assumed, so I thing we're alright in the gain department. Regrettably, the differential pump pressure is an EPICs channel, so I can't get an ASD of the performance above ~8 [Hz], but I'll post more on that in the future comment.

- Differential Pressure Noise supposedly coupling increases with actuator force request, but I've not found this to be true empirically. Check out the table below. Colors of the text help indicate which requested DC offsets are small, and which are large (dark green is smallest, then light green, gold, orange, with bright red is largest, in bins of 50 [micro-whatevers] and anything higher than 200 [micro-whatevers] is marked as bright red). Cells shaded in gray show coherence between the differential pressure and the HEPI L4Cs.

There is no discernable pattern:

Here're what patterns I was able to glean from the above table and attached plots:

• Every chamber has a large coherence with HP
• All chambers coherence drops off gradually below ~0.1 [Hz], probably because the measurement is hitting the L4C noise floor. Similarly, the coherence drops off above ~2 [Hz] because the table motion becomes dominated by IPS noise reinjected via the feedback loops
• Pressure is typically coherent between 0.2 and 2 [Hz] in Z, where RZ is typically coherent between 0.02 - 0.2 [Hz] (though note that the sensor noise limitations of this statement from above)
• BSCs have stronger coupling to pressure noise than the HAMs. One might argue this is because the actuators are pushing more (~5 [ct_{rms}] on HAMs, 50 [ct_{rms}] on BSCs calculated down to 1 [mHz]). BUT HAM6 has a huge vertical offset, but now where near as heavy a coherence.
• Input HAMs have no RZ coupling, but output HAMs and BSCs do
• Only HAM2, HAM5, and ITMX have some X & Y coherence with pressure. HAM2 in X, HAM5 in Y (of course), and ITMX in both. All between 0.6-0.9 [Hz].
• It looks like a pretty bingo board, doesn't it? Thanks for reading this far!

- My best guess at this point is that it depends on the intricacy of how the piping is laid out between each chamber and the pumps. But it's only a guess, it's the only thing I know that significantly different between all chambers.

-------------------

DTT templates for this data live here:

/ligo/svncommon/SeiSVN/seismic/HEPI/H1/Common/

2015-01-23_H1HPI_ActuatorDrive.xml

2015-01-23_H1HPI_PumpControllerNoise.xml

The stopband filter we put in the ETMX OL servo yesterday seems to have done the job of preventing the ringups:

In the attached trend of the OLPIT 3-10 Hz BLRMS, you can see the ringup start around 6AM local time this Sunday, the 25th.

Around noon on Monday (1800 UTC), Evan and Alexa start damping the mode using the bandpass filter in the OL PIT servo. They stop around 2100 UTC when the mode is small. It then rings up for the next 7 hours until we turn the stopband filter on.

Then it rings down with a 1/e time of ~4 hours (which implies a bounce mode Q of ~440,000 if nothing else is driving it).

We should make sure to install these on all of the test mass OL servos.