Red team,

We wanted to calibrate the POPAIR_B demodulated signals into something meaningful. We calibrated them into uW in the digital system using the measured calibration factors (see alog 9845). See the attached for how they now look. Also, we accordinly corrected the LSC trigger thresholds in the guardian which depend on the POPAIR_B_ calibration. We confirmed that the guardian works fine with this new calibration.

Mitchell & I got the Horizontal L4Cs leveled this morning on WHAM4.  One Dial Indicator tree had been completely dislodged from the system.  Please try to avoid these and certainly let us know when you possibly disturb them, thanks.  No issues to report in the L4C leveling.

Next, Actuator attachment (2 days) then the doors.  Vertical L4Cs can go on after the doors.

Since an SR560 can only take 1 V dc input, and can only output 10 Vpp, you can use this box to extend the input and output ranges of an SR560 by a factor of two.

This morning I went to the EY and floated the ISI. Fairly straight forward, with no difficulties to report. I also adjusted lockers, fixed some cabling issues and re-gapped the CPS's. I then went into the chamber below (mostly to retrieve some hardware I dropped (sorry Betsy)) and plugged in a cable for Richard.  I left the ISI locked, in case any other teams need to go in and work. As far as SEI is concerned, we are ready for TF's.

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=10331

To recap, OLs, bias sliders and BOSEMs were calibrated using baffle PDs (baffle PD placement is here: https://alog.ligo-wa.caltech.edu/aLOG/uploads/9087_20131224160343_alog.jpg).

OL for ITM has a factor of 2 error somewhere, and the sign convention for OL PIT is inconsistent with SUS convention.

OL for ETM doesn't have a factor of 2, the sign convention for OL PIT is good but YAW is not.

I telneted into the procServ IOC for end Y and saw the following error messages:

epics> attempting to connect to host: 10.1.3.64 port: 8003
Error: tcp_connect: socket: Too many open files
CAS: Client accept error was "Too many open files"
attempting to connect to host: 10.1.3.64 port: 8003
Error: tcp_connect: socket: Too many open files
attempting to connect to host: 10.1.3.64 port: 8003
Error: tcp_connect: socket: Too many open files
attempting to connect to host: 10.1.3.64 port: 8003
Error: tcp_connect: socket: Too many open files
CAS: Client accept error was "Too many open files"

I restarted the IOC, and the errors did not reappear, but none of the expected state reporting messages were shown. I tried pinging the Comtrol at 10.1.3.64 and did not get a response.

It appears that the DAQ switch for EY (sw-ey-h1daq) crashed when trying to SSH in, at about 11:05AM PST, at least looking at the uptime.  (Yay.)  I didn't have the CDS overview up and handy to see for sure if the DAQ data for EY was affected for the period of the reboot, but I would assume it was; it was back to normal by the time I pulled up an MEDM to check.  'Luckly', the EY systems do not seem to be in active use at the moment.

Since the measurement is not done yet, I asked Jeff to give me the model of the TF from PUM to the test mass angle to angle.

Since I don't know enough about the model, I made the model generate the TF data, and used my wrapper for vectfit3 named happyVectfit to fit the model TF and invert it. This way when the real TF is measured I can use the same script without much modification.

You want to give happyVectfit a large order of fit, which initially produces many useless poles and zeros, but the script weeds out useless ones automatically, making things almost always hands-free. If you want you can give the script some criteria regarding what poles/zeros are useless.

~controls/keita.kawabe/fit/invertPUM2TSTmodel.m looks at the model, calls happyVectfit, inverts the fit, discards unstable poles and outputs plots (attached) as well as foton-compatible filter definitions.

In the attached plots, each DOF for each mass has two pages, the first one being the model TF and the fit, the second one being the filter generated and the residual that is just a pendular type TF. The difference between ITM and ETM is wire VS fiber.

According to Jeff the PIT resonance of the model is inconsistent with reality so we still need to wait for the real measurement.

Just to make sure, the newly generated filters are put in H1:SUS-ITMX_L2_DRIVEALIGN_P2P, Y2Y,  ETMX P2P and Y2Y as invP2P and invY2Y.

Here is the list of commissioning task for the next 7-14 days:

Green team:

• Automate auto-alignment for green.
• Add normalization and trigger to REFL_DC_BIAS path.
• Use REFL_DC_BIAS to stabilize the red.
• Noise measurement between red and green stabilized on red.
• Make a mode scan of the red resonances.
• Commission the length feedback path to the ETM top suspension point to suppress microseism. 

Red team:

• Investigate the robustness of the 3f lock in presence of an arm cavity.
• Diagonalize PRM/PR3 drive.
• Center the red QPDs in EX.
• REFL_A commissioning.
• PRC length measurements.
• Optimize the thermal compensation of ITMY.
• Investigate the REFLAIR45 whitening filter issue.

Blue team (ALS WFS):

• Beam quality investigation (potenial)..
• Check out actuation function and commission compensation filter.
• ETMX optical lever.
• Automate drift alignment.

Blue team (ISCTEY):

• Move tablel to EY
• Cut panel and install light pipe.
• Install the on table cabling.
• Check out ALS electronics in EY.
• Prepare noise eater remote switch.
• Add WFS.

TMS:

• Beam alignment in final position.

SEI/SUS team:

• Measure length-to-angle TFs
• ETMX drive diagonalization for length and angle.
• ITMX drive diagonalization for angle.

Kiwamu, Yuta, Stefan

Since all our OLG functions in PRMI never really made any sense, we locked PRY and carefully measured the actuation functions from BS to REFL_45_I and from PRM to REFL_45_I.

Plot 1 shows both BS and PRM transfer functions in ctsREFL45 / cts ISCinf drive (i.e. total actuation function). Both are closed loop corrected.
The BS makes sense: it is almost 1/f^2. I don't understand the PRM - need to sleep over it.

Plot 2 shows the OLG and the CLG.

Plot 3 is a snapshot of (almost) all relevant settings.

The data is in ~controls/sballmer/20140302:
BSdrive.xml
PRMdrive.xml
data/BS2REFL_mag_rad.txt
data/PRM2REFL_mag_rad.txt
data/plotIt.m

To do next: 
-Understand PRM: for one we should check that the acquire mode TF of PRM M3 is as expected.
-Fit inverse actuation filters that make PRM and BS match

For the green team:

The IMC ASC gain was set back to 1 from 0.25.

While Yuta claimed that the recycling gain was roughly 3 for the 45 MHz sideband (alog 10441), I did an independent estimation of the power recycling gain.

I got a recycling gain of about 0.6 for the 9 MHz sideband based on the measured aboslute RF power on POPAIR_B at 18 MHz.  Hmmm....

This estimation relies on the absolute power on the POPAIR_B and therefore it is less reliable than the ordinary unlocked-to-locked-comparison measurement. Note that the ring heater on ITMY was off when measured. Also, the detail of the estimation is attached.

- - - POPAIR_B_RF18 calibration:

According to alog 9845, the PD was calibrated to be 7803/(5.13 mW x 0.93 x 0.1) = 1.6e7 counts/W at 18 MHz. Since it gave 18000 counts when it was locked, this corresponds to

Pam@POPAIR_B = 18000 counts / 45 dB whitening gain / 1.6e7 counts/W = 6.2 uW at 18 MHz.

- - - Estimation of the recycling gain:

There are three mirrors which attenuate the 9 MHz sideband on its way to the POPAIR_B diode.

• PR2: T = 229 ppm
• M12 in HAM1: R = 90%
• BS on ISCT1: R = 50%

Then assuming the 18 MHz beatnote is only made of the 9 MHz sideband, we get an AM component of the light at the diode:

P_am@POPAIR_B = 2 x J1^2 x Pin x  Gpr x T_PR2 x R_M12 x T_BS,

where Pin is the incident power on PRM, Gpr is the power recycling gain. If we assume that the modulation depth for 9 MHz is 0.17 (alog 9979) and Pin = 8.8 W x (Timc 80%) =  7.04 W, the power recycling gain Gpr should be

Gpr = 0.594

First PRMI noise budget from the NB tool is attached.
Optical gain estimated from the openloop transfer function measurements are 5.5e3 W/m for MICH loop, 8.6e4 W/m for PRCL loop.
Power recycling gain estimated from this optical gains is ~ 3. This estimation was done by comparing the optical gain in simple Michelson and PRMI MICH.
Note that this estimation assumes perfect diagonalization of MICH and PRCL loop, but actually they are not diagonalized yet.

[Method]
1. Lock PRMI on sideband using REFLAIR_A_RF45_I_ERR and Q_ERR (see alog #10427).

2. Take OLTF of MICH loop and PRCL loop.

3. Keep it locked for a while to take feedback signal data (H1:LSC-MICH_OUT_DQ and H1:LSC-PRCL_OUT_DQ) for the noise budget. Data I used started from Feb 28 2014 18:25:00 UTC (local Friday morning).

4. Use the NB simulink model to plot OLTFs. Change optical gain for MICH loop and PRCL loop to match those with the measured OLTFs. Here I assumed that the error signal from BS motion only appear in REFLAIR45_Q, and PR2/PRM motion only appear in REFLAIR45_I. See attached Simulink diagram I used. Optickle block is not used since we want to make the measurement based NB model. The model lives in /ligo/svncommon/NbSVN/aligonoisebudget/trunk/PRMI/H1.

5. Use the same model to plot noise budgets for MICH loop and PRCL loop. Sensitivity curve is estimated from the feedback signal data.


[Result]
1. OLTF_MICH_1077647116.png: OLTF of MICH loop from the measurement and the model. UGF is ~6 Hz and phase margin is ~40 deg. For the model curve, optical gain of 5.5e3 W/m was used. The measurement and the model agrees pretty well.

2. OLTF_PRCL_1077647116.png: OLTF of PRCL loop from the measurement and the model. UGF is ~60 Hz and phase margin is ~30 deg. For the model curve, optical gain of -8.6e4 W/m was used. The measurement and the model agrees OK except for the dip at ~13 Hz, which comes from closs coupling with MICH loop. This is because we only use BS for MICH loop, but BS also changes PRCL.

3. NB_MICH_1077647116.png, NB_PRCL_1077647116.png: Noise budget for MICH and PRCL loop. Note that seismic noise is not real (copied from LLO model). Sensor noise is currently not contributing very much. MICH motion is larger than PRCL motion (because of BS motion?).


[Discussion on PRMI optical gain]
1. Measured optical gain (from BS motion * sqrt(2) to REFLAIR45_Q) for simple Michelson was 1.9 W/m, including the cable loss (see alog #10213). The things changed in MICH loop for simple Michelson and MICH in PRMI are;

                       MI        PRMI MICH
PD whitening gain      45 dB     0 dB
H1:LSC-MICH_GAIN       900       5    
output matrix for BS   0.05      1
measured optical gain  1.9 W/m   5500 W/m

This gives overall gain ratio of MI/(PRMI MICH) = 1.3. Since the UGFs for simple Michelson and PRMI MICH loop was 8 Hz (see alog #10127) and 6 Hz respectively, this ratio is consistent.

2. Optical gain ratio between simple Michelson without PRM and PRMI should be approximately equal to the power recycling gain (PRG). However, since we did optical gain measurement for simple Michelson with PRM misaligned, measured optical gain will be smaller by factor of T_PRM^2. Thus, the ratio between simple Michelson with PRM misaligned and PRMI will be approximately Gp/T_PRM^2. So, estimated power recycling gain is;

Gp ~ 5.5e3/1.9 * 0.03^2 = 2.6

Designed PRG for PRMI is 58 according to LIGO-T1300954. Considering the closs-coupling between PRCL loop and MICH loop, this estimation seems to be an upper limit to the actual PRG (see below).

3. 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, simulated ratio between diagonal elements is PRCL/MICH = 3.4e6/1.3e5 = 26. Our optical gain estimation gives 8.6e4/5.5e3 = 16.
Considering the fact that we are ignoring the off-diagonal elements in the optical gain estimation, I think this is reasonable. For example, BS to REFL 45Q could be 1.3e5+6.4e4 W/m and 3.4e6/(1.3e5+6.4e4) = 18.


[Next]
- Measure PRMI sensing matrix, compare with the simulation, and use it in the NB model
- Update the simulink model so that it can handle off-diagonal elements
- Output matrix diagonalization for PRMI
- Include online seismic noise, frequency noise and intensity noise in the NB model

The green team had some sucess today.

We saw that there is a large wandering peak (similar to what we have seen in the IMC alog 10289 alog 10327) in COMM PFD Imon.  This PFD chassis is directly under the diff RF doubler, by disconnecting the 79MHz input from this doubler we saw the peak become much smaller.  We are leaving this unplugged since we don't need it yet. (Alexa has some movies of the two wandering peaks)

The Xarm guardian is working, at least the states up to LOCKED_W_SLOW.  We didn't test the dither alingment states since the dither alignment isn't really working anyway.

The COMM PLL slow feedback to the IMC VCO had low bandwidth, which was limited by the randomization in the VCO servo library.  Daniel edited the low noise VCO library, the servo now has two modes, internal where the frequency comparator is used for an error signal, and external, meant for use with the COMM PLL.  The bandwidth is now limited to about 1 Hz, by the VCO response.  Right now we have the gain setting for the COMM PLL slow feedback set to 14000Hz/V, and the ugf of the IMC VCO servo set to 0.8Hz.  This seems stable.  We also turn this off after the COMM handoff now. 

We found a few gremlins in the COMM handoff-  with the change to LSC input matrix our script was no longer setting the matrix element.  For some reason the fast path was disabled in the REFL servo.  Both of these things could be solves with state control code or for the time being by improving the script/writting a guardian. Now we are reliably doing the COMM handoff, which is stable for ~20 minutes to a half an hour right now.  I've just committed the handoff and down scripts to the svn. 

We rewired the REFL_DC_BIAS, so now it is routed into the CM board input 2

Once we had this locked we started looking at the IR transmission.  When the alignment is good, we stay within about 160Hz (the transmitted power wanders over the peak back and forth, but doesn't move as far as we have seen some nights.  We have seen that the amount of noise we see depends on the alingment. 

We found the IR resonance, moved the ETM in YAW, and found the resonance again.  We made three measurements like this and got 400Hz/urad.  When the alingment was worse this measurement got harder.

It seems clear we need a good alingment to have a chance of locking COMM on resonance.

Right now COMM has been locked for half an hour.

Before starting measuring Pitch to Pitch on ITMY, I realized the oplev signal was oscillating at high frequencies. I took a spectra and compared with other oplevs, and the noise floor from 1000Hz is ~2 orders of magnitude higher compared to ITMX. Thomas pointed out that this oplev doesn't have an analog whitening filter yet, so we should double check when it will be installed.
dtt template was saved under SusSVN/sus/trunk/QUAD/H1/ITMY/SAGL2/Data/2014-02-28_Oplev_Spectra.xml

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.