While pulling Dial Indicators at BSC9 yesterday I eyeballed the fluid catches and found the horizontal full and starting to drip.  I cleaned up the catch and reinstalled.  This hasn't been leaking as badly as the BS V2 had been but only no drips is tolerable.  Changing this out will take HEPI down for a few hours--look for that next Tuesday.

HugoP reported on 12 Feb that we had an issue with the EndX HEPI being unable to tilt completely.  We were requesting 390000nrads but only getting 350000.  Hugo pushed it more and it went more but it would never go to the fuly requested value.  Hint, hint--like there was an offset in the path...hummmm

I can't find an entry in the alog around Jan21, when this offset in the position request showed up (see Hugo's first link.)  However, when I look a little deeper I find the offset was increase to 39000 on Friday Jan 17 by me to run the RY Tilt manually (I guess it shoould have been 390000.)  It looks to me that on Monday the 21st, myself or Sebatian turned the HEPI position loops on but failed to turn off the offsets giving the offset observed since then.  Obviously our 'greening' of the system must be more robust.

I found this yesterday after the RCG upgrade reboot attempting to get the system back on.  The safe.snap was problematic so Dave reloaded form the 9am burt.

So by removing these offsets, the HEPI will now tilt that much more.  If the alignment is intolerable, change the target/current setpoint on the DC BIAS medm from -389800 to -350000.

Pretty much as Fabrice directed and Shiela & Kiwamu report .  One notable: The ITMX HEPI is off, not tripped.  I think the safe.snap/burt restore process/setup for the SEI is troubled and needs attention.  I guess that mainly means my job.

Unless someone tried to get the ITMX HEPI on and then left it in an unusual state, it came up screwy: Specifically--the Master switch is closed and the ISO gain is 1.0 but the Position Bias Screen is all zero.  All the switches and filters are off on the IPSINF screen but the Switches are on and the filters are off on the L4CINF page.  Etc etc... 

This morning, Yuta complained that the alignment of PRY changed a lot and therefore he had to tweak either BS or ITMY by 60 urad or so --- of course, HEPIs and ISIs were tripped on ITMY and BS (see alog 10333).

After untripping them, we comfirmed that the alignment came back to where it should be without touching the suspension biases. The ISIs are currently in the damping mode.

They are now:

• BS
  • HEPI
    • Level 2
  • ISI (see Fabrice's alog also )
    • stage 1 damped
    • stage 2 damped
    • no isolation engaged
• ITMY
  • HEPI
    • Level 1
  • ISI
    • stage 1 Level 3 isolation damped
    • stage 2 Level 3 isolation damped

I found that ITMY had been tripped at the L1, L2 and L3 watchdogs. I untripped them. It is now in "aligned" state.

Arnaud, Sheila

We want to try the ETM drive diaonalization.  One reason is that we can see that our longitudnal feedback to the top mass is causing pitch motion of the optic, and we will need the full drive diagonalization when we get the Y arm anyway, so we might as well do it now.  

We had some disscussion about how to balance the coils when there are only 3 osems, in the end we decided to just do length 2 yaw, and then move on to measureing transfer functions.  Tonight Arnaud and I had a first attempt at doing the length 2 yaw measurement, we just applied DC length offsets and used the OpLevs.  This may need to be corrected if the OpLev calibration is revisited tomorow....

When we started there was a -0.004 in the length 2 yaw drivealign matrix, we could not tell from a search through the alog and talking to various people in the control room where this number came from, possibly it was copied over from ETMY.  We have now replaced this with -0.0024.  

Attached is a plot of our measurements and the script we used. 

Daniel, Ed, Yuta, Stefan, 

After this morning's boot fest we noticed that the IMC reflected beam was completely misaligned, missing camera and WFS, and barley hitting the LSC diode. Interestingly, the IMC still locked with good build-up. We checked HPI, ISI and all involved SUSs for any drift. None showed any. Also, the PRX cavity still nicely locked. So we concluded that some mirror on IOT2L must have moved, and realigned that whole beam path. Everything worked fine again afterwards.

In the process we also had accidentally moved an ASC POP picomoter (#6) horizontally (yaw). We were able go find the beam again, but once again confirmed that these picomotors are hugely asymmetric, i.e. the counters are only useful for suggesting an axis and direction.

Written by Yuta

This morning, I could dither PR2 and PRM from ASC-ADS, but I can't now.
For example, even if I put on H1:ASC-ADS_PRM_PIT_OSC, the signal doesn't show up at H1:SUS-PRM_M3_ISCINF_P_IN1.
Since it did this morning(6AMish~10AMish), I suspect this is related to the boot festival today.

If I lookup the simulink diagram, h1asc.mdl has H1:ASC_SUS_PRM_PIT_DITHER, but h1prm doesn't.

[PRMI dither alignent work this morning]
We want the alignment automation to speed up the PRMI commissioning.

I checked the guardian script for PRX dither alignment Evan and I made yesterday. It now works for PR2 dither alignment. PRX_ALIGN state closes PR2 (and PRM) dither alignment loop, wait for a while, and offloads the feedback offset (e.g. H1:SUS-PR2_M1_LOCK_P_OUT) to the alignment slider values (e.g. H1:SUS-PR2_M1_OPTICALIGN_P_OFFSET).
For PRM, I had to lower the excitation frequency for pitch/yaw from 14/11.5 Hz to 5.4/7.2 Hz, and excite not only M3 but also M2 to get the error signal. I haven't checked fully yet, but the guardian script should also work for PRM dither alignment.

Next work is to do BS(or ITMY) alignment using PRY.

We have been experiencing issues with the BSC-ISI watchdogs since the models have been re-compiled this morning. They are not operating as they should. It may or may not be related to the rcg code update (it could also be due to some piece of SEI code that should not have been updated from the svn, for example). We have not found any obvious cause of the problem yet. The BSC-ISI units are currently working fine and safely in damping mode. As a measure of precaution, the master switches will be turned off at the end of the day.

The cdsRampMuxMatrix part, which is new to RCG 2.8 (and updated in 2.8.3), allows for pre-writing a new matrix and then loading it with a specified ramp time from the current values to the new ones.

This part has been swaped into the PD_DOF_MTRX position in the main LSC library part in:

USERAPPS/lsc/common/models/lsc.mdl

The h1lsc model was rebuild/installed/restarted, and has been tested and seems to be working as expected.

The channel interface to the matrix has now changed.  The readback channel retains the same form as the non-ramping matrix, but new channels are added to write the new matrix:

Scripts/guardian will need to be modified to write new matrix values accordingly.

The MEDM screens for the input matrix were updated with a new interface for the matrix.  The updates screens are (screenshots below):

USERAPPS/lsc/common/medm/LSC_CUST_PD_DOF_MTRX_VAC.adl
  USERAPPS/lsc/common/medm/LSC_CUST_PD_DOF_MTRX_AIR1F.adl
  USERAPPS/lsc/common/medm/LSC_CUST_PD_DOF_MTRX_AIR2F.adl
  USERAPPS/lsc/common/medm/LSC_CUST_PD_DOF_MTRX_CM.adl 

Each matrix element is split vertically, with the readback of the current value at the top, and the new value at the bottom.  The boxes are colored to indicate the state:

• new different setting not yet applied
• ramping to new value
• current setting is non-zero

The "Kissel buttons" on the main LSC_OVERVIEW screen did not have to be modified since the readback channel did not change.

After much of the day was spent for recovery from maintenance, we wanted to make green WFS wider band, for which we need to redo penultimate mass to final mass pit to pit and yaw to yaw measurement, and since we're using OLs, and since OL whitening were bad but are now good, and since ISI is performing much better than the beginning of the HIFO_X,  we decided to calibrate OL using baffle PDs again. And since we might want to use TMS for alignment we also did the calibration measurement for TMS.

We only had time for TMS and ITMX for today.

TMS:

Used H1:AOS-ITMX_BAFFLEPD_1_POWER and 3_POWER (3 is actually connected to PD4). Also recorded H1:SUS-ETMX_M0_DAMP_P_IN1 and H1:SUS-ETMX_M0_DAMP_Y_IN1 and used tdsavg.

"delta claimed" is the TMS rotation measured as the difference of bias offsets between PD4 and PD1, "delta physical" is derived from baffle diode drawing and the arm length of 4000m (see the drawing in this alog: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=9087).

Positive PIT means the beam points down. Positive YAW means the beam rotates counter-clockwise viewed from the top.

ITMX:

Used H1:AOS-ETMX_BAFFLEPD_1_POWER and H1:AOS-ETMX_BAFFLEPD_4_POWER. Also recorded H1:SUS-ITMX_L3_OPLEV_PIT_OUT and H1:SUS-ITMX_L3_OPLEV_YAW_OUT.

"delta reality" is half the angle formed by PD4, ETM and PD1 as the beam rotates twice the angle of the ETM.

Positive PIT means that the optic points down. Positive YAW means the beam rotates counter-clockwise viewed from the top. OL has different sign convention from SUS for PIT here.

Didn't have time to do ETMX.

Not sure if Filiberto is complete but maybe...

As far as SEI work goes:

CPS racks are located and all wired up sans sync cable.

~75% of the in-air cables going to the Feed Thrus are Strain Relieved.

The harder half of the Dial Indicators are in place.

Daniel, Sheila, Alexa,

We pinned down the wandering peak in the IMC error signal.  It was a beat note between the fixed frequency 78.2MHz and the IMC VCO.  Moving the IMC VCO frequency (using the tune offset) moves it, it dissapears when the 79.2MHz is off. It becomes very small when the cable from the RF pacth panel in R1 to the doubler for the fiber distribution is disconnected from the patch panel, and can be small when the able is connected at the patch panel but not at the input to the doubler, perhaps depending on where the cable is.  Disconnecting the output of the doubler has no impact.  It seems like a purely electrical problem.

We still do not know why the UGF has changed, but the of the IMC error signal measured at Imon is 1.5V at the moment. 

LVEA Laser Safe

Hanford Ground Water coming check well 
Apollo working at End-Y

08:35 Filiberto – Going to End-Y 
08:35 Aaron – Going to End-X
08:47 Hugh – Going to End-X
10:00 Joe & Craig – Working in H2-PSL enclosure
10:32 Hugh – Dropping of electronics at HAM5
10:33 Corey - In LVEA West bay looking for parts 
10:39 Dave – DAC restart
10:41 Dave – Restart PSL, IOP, User Models, etc
10:48 Travis – Open rollup door in North Bay moving in Argo arm
11:25 Jax – Working in squeezer bay
11:25 Aaron & Alexa – Going to End-X to test Noise Eater function 
12:09 Hugh – Getting tools from HAM4/5 area
12:55 Karen – Cleaning at End-Y
13:05 Hanford Ground Water on site
13:20 Travis – In LVEA working on ITM monolithic build
13:40 Dave – Restart DAC
13:50 Dave – Recompiling/Restarting all the HAM-ISI models
13:52 Filiberto & Aaron – Working at End-Y
14:00 Kyle – Craning RGA over Y-Beam Manifold 
14:00 Joe, Chris, & Craig – Working in H2-PSL enclosure
14:05 Hugh – Working at End-Y
14:20 Justin – LVEA laser hazard
14:45 Ed & Evan – Working on IOT2R table
15:03 Alexa – Going to End-X 
16:00 Rick & Craig - Working in the H2-PSL enclosure

The monuments are set on the floor that will be used to align SRM, SR2, SR3.
802 elevation target will be used to heights

For comparison with experimental observations I ran some more simulations of SB locked PRMI POP 18MHz buildup.

The attached plot shows the modeled POP 18MHz signal as detected directly in transmission of PR2 (i.e. no additional POP pick-off optics considered). I tuned the demod phase to put all the signal in I phase at the starting (cold) point on the left hand side of the x-axis. The Q phase signal is also shown on the plot, along with the AS port power (unavaliable in practice of course).

The different colors represent different ITMX non-thermal substrate lens cases, ranging from -15uD to 15uD power. I wanted to look at a range of ITMX lens cases because of the questions thrown up by the beam size measurement analysis I posted on Friday (10237). As usual, I expect the ITMX lens is indistinguishable from PR2-PR3 distance offset. I also assumed no susbtrate lens in ITMY: this could certainly impact the required heating to optimize the power buildup. However it would also affect the maximum buildup level due to a) changing the PRC mode mismatch with the IMC beam and b) changing beam sizes at the BS thus affecting clipping (unmodeled here).

Just to clarify, here are some specific things included in the model:

• Input beam power 10W
• Input beam defined by IMC mode, propagated through PMMT to PRM
• PRX eigenmode calculated between PRM and ITMX HR surface
• PRY eigenmode calculated between PRM and ITMY HR surface
• Mode mismatches occurring at PRM (IMC<->PRY) ans BS (PRX<->PRY)
• TEMs up to order 4 considered in calculation
• ITMX non-thermal substrate lens (varied)
• ITMY thermal lens from ring heater (varied)
• MICH lock using REFL45Q signal
• PRCL lock using REFL45I signal
• Design value of PR2-PR3 distance, with measured value of PR3 Rc
• IMC FSR = 9.0994548MHz
• 9.0994548MHz modulation depth = 0.1, sidebands up to order 2 considered
• 45.497274MHz modulation depth = 0.07, sidebands up to order 2 considered
• ITMY ring heater actuation gain = -13.6uD/W

And some specific things not included in the model:

• Clipping at the beam-splitter
• Non-thermal substrate lens in ITMY
• Thermal lens in ITMX (should be none anyway)
• Any kind of surface figure maps beyond Rcs and lenses
• BS lens / curvature

Maybe the best short version I can give is this:

If the beam size measurements are to be believed, and assuming no ITMY non-thermal susbtrate lens, I expect ~8W should match ITMX and ITMY reflected curvatures best, and this should give the best PRMI buildup (about a factor 9 better than the cold state). In this case, the PRMI buildup should be relatively unaffected by BS clipping, as the beam sizes remain small.

If the beam size measurements are discounted and we assume the -12.5uD lens from surface figure measurements (and still no ITMY non-thermal lens), I expect ~9.8W should match ITMX and ITMY reflected curvatures best. This is unlikely to give the best PRMI buildup, as BS clipping starts to dominate losses as the PRY mode approaches the PRX mode and the contrast defect gets small. We've seen something of a trade-off between CD and BS clipping in determining PR gain at LLO, coming largely from the -80km lens setting the PRY beam size at the BS significantly larger than the design. We'd expect the same thing at LHO but switched between X/Y.

I include the simulations files here. It was run with the Matlab script "runlockedPRMIbuildup.m" calling the main kat file "H1_PRMI_RH_POP18.kat". It takes quite a while to run, due to the HOMs and locks, so included the .mat file with the results for convenience. You can just run the second block in the Matlab script to plot the results saved in the .mat file. If running the finesse simulation itself, you should use Finesse v1.1 or higher, which has the simultaneous sideband field computation feature included (see here for details).

This is from last week.

We briefly measured the distance between optics and such, and used nanoscan to measure beam width/profile at various places though they were very very ugly.

See attached scribbling for layout (all dimensions in inches). Mirror names are arbitrary.

Measurement points are indicated by alphabet from A to I. Measurement points with prime (G'-I') means that the first lens in WFSB path (LWFSB1) was removed during the measurement.

The rest of the attachements are the nanoscan result. WFSB1.jpg-WFSB4.jpg=measurement point A-D. WFSA1.jpg and WFSA2.jpg=measurement point E and F. WFSC1.jpg-WFSC3.jpg=measurement point G', H' and I'.

J. Kissel

Given that this morning's ETM motion provided for difficult arm cavity locking and CARM hand-offing again, I've continued to pursue the long-term stability of the X ARM ISI Performance, by studying the ISI performance at 3 different times.

Here's what we learned (or re-learned) from the study today:
(1) Today (2014-02-13 17:00 UTC) was a really high-wind day. Yesterday (2013-02-13 04:39 UTC) was a medium-wind day. Two days ago (2014-02-12 01:00 UTC) was a low-wind day. The green team really liked two days ago, they were marginally happy with yesterday, and could not get anything done today.

(2) From Robert: "At the X-end, wind, which comes primarily from the Northwest and West and beats against the side of the building, tilting the building, slab, and ground. This motion is seen as increased signal in ground seismometers between 0.02 and 0.1 [Hz]. The corner station, being a shorter, squat building is much less sensitive to wind."

(3) In the current configuration, with Level 3 controllers and TCrappy blends, The longitudinal motion of the ETM suspension point is dominated by RY motion between 0.2 and 2 [Hz].

(4) The Level 3 controllers and TCrappy blends attempt to get awesome performance between 0.2 and 2 [Hz], because -- during low-wind days -- the QUAD pitch motion at the test mass between 0.3 and 0.7 [Hz] dominates to cavity motion. When larger than ~80-100 [nrad/rtHz] @ ~0.5 [Hz], the 0.3-0.7 [Hz] angular fluctuations make holding the optical gain constant difficult, and due to the poor quality of the coatings in green the cavity is more likely to fall out of lock.

(5) The wind / slab tilt does not obviously increase the ground seismometer signal between 0.3-0.7[Hz] band.

(6) During high-wind days, 0.02-0.1 [Hz] pitch motion of the ETM supersedes the 0.3-0.7 [Hz] motion, increasing the RMS motion so much so that the green VCO regularly saturates, kicking the cavity out of lock, again above ~100 [nrad] RMS.

(7) The TCrappy displacement sensor blend filter has a broad, factor-of-three-ish gain-peaking amplification hump between 0.01-0.07[Hz]. The filters were pretty good copies of L1's blend filters, where wind and 0.02-0.1 [Hz] motion is regularly pretty darn small. It's merely unfortunate that our ground motion is so volatile and different at these frequencies that we won't be able to use the exact same blend filters between the two IFOs.

(8) In order to reduce the cavity motion below the saturation limit of the VCO, one could try to just offload the bulk of the control authority to HEPI along the IPC tidal path up to, say a little past the microseism (but before the QUAD suspension resonances to keep the loop design simple). BUT the ISI's TCrappy filters blend at ~0.06 [Hz], with a *ton* of loop gain from the Level 3 isolation controllers, so any motion injected into HEPI will get ignored / suppressed by the ISI's inertial sensors above the blend frequency.

(9) The TCrappy blend filters we used in the design of the Level 3 controllers, and those particular blend filters are only "psuedo" complementary. Though this hasn't been thoroughly tested or confirmed, the belief that this means that TCrappy blends can *only* be used with the Level 3 controllers, and vice versa. The ISI had tripped one or two times while switching from this blend configuration to another, but there's not yet direct evidence that this marginal in-complementarity was cause.

(10) The ITM is consistently performing better than the ETM, as measured by the optical lever -- but remember, it's unclear whether we can trust the short-armed ETM lever to be measuring pure pitch below ~0.5 [Hz].

(11) The ITM optical lever's signal consistently has some high-frequency fuzz on it, above 0.5 [Hz] that's clearly visible in the SUM. Stefan suggests we should investigate / replace the laser head to make sure this isn't mode hopping of an old dying diode.

(12) One can monitor the blend filter status by watching the H1:ISI-ETMX_ST*_BLND_*_*_CUR_SWSTAT channels. At least in this case where we are using all TCrappy filters in FM5 of the filter banks, with the input, output, offset, and decimation buttons on, the bit-word is 7184.

In conclusion, 
- We need to pay attention to tilt, not just the translational direction of the ISI.
- Our performance is volatile, depending on the weather, so need to consider having windy-day vs. calm-day blend filters that we regularly are able to switch between without trouble.
- We still have work to do on the ISIs. Sensor correction, which has not been commissioned on either X ARM platforms can perhaps help, but maybe not if we are blending so low. We should most certainly investigate a set of blends with less gain peak in the wind band.