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).

To eliminate the number of parts problem I rewrote a section of the ODC master as simple c code. Functionality and channel names stayed the same. The parts count dropped from 3549 to 536.
The function that now does most of the work is MASKING_MATRIX in ODC_MASKING_MATRIX.c.

I also added a hook to include IPS error checking to that c-function.

sys/h1/model/h1odcmaster.mdl
sys/common/model/ODC_MASTER_PARTS_V2.mdl
cds/common/src/ODC_MASKING_MATRIX.c
SVN revision 7282.

10:40 Check which models had new INI files after make install

13:47 Check new ham isi INI files, add new dust channels

14:15 new h1odcmaster file, channels unchanged, chnnums changed?

Stefan, Jim and Dave

Stefan created a new h1odcmaster.mdl model which drastically reduced the number of "parts to process" from 3,549 to 536. We started it after crashing the h1oaf0 for the last time, and then restarted it with no further crashing.

It required a DAQ restart.

Plotted the End-Y dust monitor data for the last 24 hours, (covering the cartridge install and subsequent activities at End-Y). Dust spikes are consistent with the cartridge installation and Apollo working on post-installation tasks. EY-DUST-1 covers from 06:00 to 12:00 02/25/14. EY-DUST-2 covers from 12:00 02/24/14 to 12:00 02/25/2014.    

I added the channels to the ini file (cds_user_apps/trunk/cds/h1/daqfiles/ini/H0EDCU_DUST.ini) and Dave B. restarted the DAQ.

Fabrice, Dave.

WP4461: rebuilt, installed and restarted the models h1isiham[2,3,4,5,6]. Manually burt restored to 09:00 the models h1isiham[2,3,5,6] as before (ham4 has good safe.snap).

I set the end X ALS laser temperature to 31.77, the set current is at 1.84, and the doubling temp is 33.81.  We have a beat note.  I realinged the IR monitor PD and it reports 63mW now (power before pick off), and the green monitor reports 1.05mW

see alog 9057 for the last time I changed these values. 

After Aaron installed the relay for the noise eater the laser came back to a set temperature of 32.9C, so we could not find a beat note at first.  Richard is testing the relay now. 

Jim and Dave

We compiled all the front end models against 2.8.3 except for the three models mentioned previously.

I installed all the models using the install-World option and a modified local rtsystab to skip aforementioned models.

I then did a DAQ restart to see if any INI files were modified which we were not expecting, and we were surprised by h1odcmaster and h1susetmy which have modified INI files. h1lsc was modified by this was expected due to Jamie's new model.

We then logged into each front end and restarted the models. Since IOP models were being restarted the sequence was

stop all user models

restart the iop model

start all the user models

As usual we had to press the BURT button on many models before they timed out.

GOTCHA. the bug which doesn't allow the h1odcmaster to be restarted without crashing the h1oaf0 computer was tested and is still there! Jim was able to take this node out of the dolphin fabric so we didnt have to re-restart anything.

PSL was the first to be restarted. I burt restored to 09:00 today and opened the shutter from the MEDM screen. All looks good.

I then viewed the safe.log files for each model to see which ones reported many connection errors. For those with more then a few dozen I manually burtrestored the following to 09:00 this morning;

hpiham[4,5,6]  isiham[2,3,5,6] sustmsy, suspr3, susim, susitmy, lsc

I tried burt restoring h1susetmy but it had errors due to a model change.

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'.

I started conlog again after the shutdown for the ntp time server install. I set it to use a new channel list with additional daq and filter module channels provided by Dave B.

The channels scanned from the autoBurt.req files are in full.txt (98,328 channels)
The additional daq and filter channels are in include.txt (24,076 channels)
A set of noisy channels to exclude are in exclude.txt (37 channels)
The set of currently used channels are in full_plus_include_minus_exclude.txt (122,376 channels)

Alexa S., Patrick T.

We added the newly installed relay to the h1ecatx1 system manager and committed the change to svn. We used Daniel's GUI to restart everything and did a burtrestore to 9 am this morning.

Jim B., Patrick T.

The conlog program was stopped.
ntp was installed on h1conlog and set to read from h1boot.
The ntp service was stopped.
A step time update was done:
25 Feb 10:19:09 ntpdate[10216]: step time server 10.101.0.10 offset -105.644733 sec
The ntp service was started.

We thought it prudent to have a spare PUM in-hand for the upcoming monolithic builds, so yesterday we started bonding ears to the PUM ITM03.  Gerardo sucessfully placed an ear on the S4 surface with an error of under 0.01mm misplacement (0.1mm is the tolerance, so well done Gerardo!).  On to the S3 ear...

There is a large wandering peak in the IMC error signal.  (measured at Imon).  A movie is attached.  We tried several things to try to pin down where this comes from.  This wandering peak also shows up in the end station PLL and goes away when the IMC is unlocked.  

This afternoon I checked out some signals from the PSL to see if there were any similar wandering peaks in them and didn't see anything.  I looked on the TTFSS Field box mixr(in2) fastm test2, on the ISS Photodiode A output Photodiode B output. PMC mixer out. Unless there are better signals to look at, I would conclude this isn't from any of the PSL loops, but the IMC itself.  

Alexa and I also tried a few things to see if the wandering peak would go away under different conditions.  It does sometimes go away, but this seems unrelated to the things we tried.  We tried:

• turning off the ISS,
• turning off the slow feedback from the COMM PLL to the IMC VCO,
• turning off the COMM PLL,
• changing the gain on the FSS,
• unlocking the arm cavity,
• misalinging ETMX.  

We saw the wandering peak in each of these situations. We also had a look at Imon with the IMC unlocked, it wasn't clear what we were looking at when the mode cleaner was flashing.  We misalinged MC1 to look at the dark noise, and didn't see any wandering peak there. We also looked at the IMC open loop gain, there are no resonances or notches there, I remeasured several times and got the same result each time. (53kHz ugf 45 deg phase margin).

Alexa noticed that the UGF is higher than it used to be: she measured it in alog 10069 to be 28 kHz. The neither the settings on the MC board nor the transmitted power have changed.  

We have not been able to do the COMM handoff tonight, although the arm cavity and COMM PLL seem to be quite stable.  

We also attempted to measure the COMM PLL spectrum using the single shot green beam, to get a measurement of the laser frequency noise.  the beat note was about 10mV peak to peak (measured with 1MOhm impedance on the scope) which was not enough for us to lock the PLL. 

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.