Alexa, Daniel, Sheila

RED TEAM: We are exciting ETMX, ITMY Pit and Yaw over night.

I have excited ETMX, ITMX Pit and Yaw, L2 test filters at various frequencies. The oplevs move from around .2urad to .5urad. In this configuration the green lock transmission ranges from 760 counts to 400 counts. Increasing the drive caused the arm to lose lock (and we assumed Keita wanted to make his measurement with the arm locked), and caused ITMX suspension to trip. Hopefully, this set up is enough for Keita's measurement. The start time was around: 8:34:52 UTC time. The excitations are being run by four awggui's on opsws7. I have attached the awggui configuration and a picture of the oplev motion on dataviewer.

We had a lot of trouble early in the evening isolating ETMX, we kept tripping the watchdog on stage 2.  We tried reseting the CPS offsets, and eventually were able to get it to isolate with Tcrappy and level 2 controllers, but the motion was rather large (~ten fringes per second).  We left stage 2 with damping only. 

Alexa, Daniel, Sheila

We normalized the refl PDH error signal, and saw that we can stay in the linear range of this signal with only ALS COMM locked. 

We first normalized LSC-X_TR_A_LF by adding a gain of 0.000154 so that the tranmission peak is at roughly 1.  We set LSC-REFLBIAS to  REFL_A_RF9_I over the transmitted power (LSC-X_TR_A_LF).  The first screen shot is the PDH, the transmitted power, and the normalized error signal as we move the COMM VCO set frequency.  In the red trace we moved the frequency by 2kHz; meanwhile, in the blue trace we moved half as fast over 1kHz.  We used Alexa's equation from alog 7054  to roughly calibrate the signal: 80Hz cavity pole/150 counts pp of the PDH signal=0.533Hz/count.

We put this gain into the REFL_BIAS filter, we will do a more carefull calculation in the morning. With this calibrated error signal we were able to measure an out of loop spectrum of the noise between the arm cavity and the PSL.  Attached are some of the spectra that we took. In the top panel the green trace is a reference with the cleanroom over HAM1 on, in the red trace we turned the cleanroom off and Alexa tried to tune up the arm cavity alignment by maximizing the green transmitted power.  This realingment clearly helped at low frequecies, and reduced the coherence with the ETMX PIT oplev. 

The RMS we measured is completely dominated by low frequency noise that changed, probably because the alignment was drifting.  The RMS down to 0.1 Hz varied from 30Hz-70Hz, we also measured an RMS of 58Hz down to 0.01 Hz.

We saw coherence with the end station PDH reflected signal above 1kHz,  coherence with the PIT oplevs (mostly ETMX, which currently has level 2 controlers on Stage 1 and damping only on stage 2) around the PIT resonances (0.4-0.5 Hz), and coherence with YAW OpLevs from 0.04-0.5 Hz.  We also looked for coherence with some of Robert's PEM sensors, we have coherence from the periscope on ISCT1 from about 50-100Hz, as we kind of expected.

Tonight the noise is much worse than it was on saturday, the transmitted power was not stable at all over time.  This might be because we don't have as good of an alignment, or be because the arm cavity motion is larger because of the problems with ETMX ISI.  We also measured the spectrum with higher and lower gains in the COMM board, higher gain did not seem to help, which is different from the situation on saturday alog 10439 . 

We completed the changes in the lsc model to include the ALS-C_REFL_DC_BIAS path. It is split off the input matrix and now has power normalization, an extra LSC filter module (LSC-REFL_BIAS), and triggers. It bypasses the output matrix and directly links to the ALS filter module which is outputed to the DAC. The DAC channel is available at the DB9 breakout panel at the ISC-R4 rack. It is intended to be wired into the CM summing node. Currently, it is wired to the second input of the common mode board. Medm screens have been updated to add the extra matrix row where needed. The new filter modules are only available from the ALS_CORNER overview screen. Model and medm screens have been submitted to svn.

PLC3 on h1ecatx1 can't be activated and run using the install srcipts.  If you open PLC control and try to login it asks you which run time system to use, if you select run time 3 it can login and seems to be running OK.

[Ed, Yuta, Stefan, Arnaud, Sebastien, Jeff, Evan]

Temperature loop

On Sunday, Stefan helped me get a stable temperature loop going for the auxiliary laser PLL. The lasers now stay frequency-locked for about 5 minutes. We take the fast control signal, feed it into an SR560 for gain/rolloff control, then attenuate a bunch, and feed it into another SR560 which sums this signal with a trimpot-controlled DC offset signal. This signal then goes into the slow control of the laser. I suspect the short lock time is due to the fact that the SR560 has no integrating feature; right now I've just set it to have a DC gain; the pole of the temperature loop is set by the thermal pole of the laser. A diagram of the loop topology will be uploaded soon.

PRMI FSR sensing: no success

On Monday, the EE shop made me a 60-ft BNC cable with LMR-195. I used this to take the raw RF signal from REFLAIR_B and bring it over to the IOT2R setup. This signal is demodulated using the PLL offset frequency as the LO, and the resulting DC trace is monitored on a scope.

This afternoon, Yuta and I stole time from the green team in order to lock PRMI and try to see if the demodulated REFLAIR_B signal would show any kind of error signal in response sto the PLL offset being swept across an FSR of the PRC. We swept from 58 MHz to 62 MHz, but did not see a clear DC response from this error signal; the DC was between -1 mV and 0 mV, with an rms noise of a few hundred millivolts. If the offset frequency was set to be near a harmonic of 9.1 MHz, the error signal would become dominated by the beat of the harmonic against the offset frequency (as one would expect).

Next, we tried looking at POPAIR_B_LF to see if we could see a DC power buildup as a function of PLL offset. We didn't see anything; the DC power fluctuated between 70 and 90 counts at all times, and showed no change in response to the PLL offset.

Addendum on PRMI Iocking

Yuta tried for some time this afternoon to get PRMI locked. The biggest stumbling block was that PRY showed no fringes. Eventually, with the help of Arnaud, Sebastien, and Jeff, it was realized that

1. ISI target values (e.g. H1:ISI-BS_ST1_CPS_RZ_TARGET) change after each CDS reboot; they must be corrected by hand. BS ISI stage 2 Rz was particularly bad.
2. Changing the signal blending from 'Start' to 'TCrappy' for BS ISI stage 1 and turning stage 2 off helps locking PRMI. When ISI settings were wrong, power recycling gain showed large fluctuations at ~0.5 Hz (presumably from the microseism), with a modulation depth of about 50%.

Jim, Sebastien

We've been seeing some weird issues all day on BSC-ISI ETMX.

After restarting the models on all the BSC-ISI platforms this morning (see post here), we realized that the horizontal (X, Y, RZ) lvl3 controllers on ST1 were all equal to an empty zpk with a gain of zero

zpk([],[],0.000000000000,"n")

First mystery.

We successfully reinstalled those filters using the seismic scripts to do so (autoquack function).

Second mystery: when we turned the controllers lvl3 on, we noticed a huge drive on the horizontal DOFs, especially on ST1-H3 (~15000 counts according to the overview MEDM screen).

After some investigation, we can see some high frequency features in the closed cloop power spectra, especially at 718.875Hz (see plot attached).

This features show up on all the axis, especially in X (which explains the huge drive on H3), and only with the lvl3 controllers (looking at these controllers in foton, they actually look fine...).

My guess so far is that there is something wrong with our foton file. Arnaud is taking some measurement right now, so I'll continue the investigation later.

Lvl2 controllers are actually engaged on ST1 and ST2 (with Tcrappy blend filters)

The external epics gateway and the vacuum alarm emailer programs were restarted after OS patches were applied and required server reboots.

Because finding the statistical uncertainty in a transfer function data point, as a function of its coherence and how many averages were taken, comes up just about every few years (e.g. the last time I saw it was in the LLO eLOG), here it is quoted in the aLOG for the next generation: 

Relative uncertainty in transfer function magnitude: 
 
d|TF|           1 - C  
----- = sqrt ( ------- ) 
 |TF|           2 C N  
 
where C is the coherence, and N is the number of averages.

Absolute uncertainty in transfer function phase:
 
                  1 - C  
d <(TF) = sqrt ( ------- )   [rad]
                  2 C N   
 
where C is the coherence, and N is the number of averages, and is in units of radians.

Ref: Bendat and Piersol, "Random Data" 2nd Ed, p317.

I exited the LVEA about 1635 pst.  I've got the two Actuators on Corner3 (SE) connected.  Three corners to go.  HEPI is unlocked.

Results of todays look at the suspended optic:

Longitudinal using the same corner cube to optic offset as measured on the test stand (454.3mm) added to the EDM shot = 5629.3mm, desired distance 5629.8, error o.50mm. Tolereance of +/- 3mm

Latitude desired tolerance (beamline) +/- 1.0mm, measurement 1.4051mm Error correction .4051mm minimum. Needs to move south direction.

Vertical desired tolerance beamline +/- 1.0 mm, measurement -1.1054mm. Error .1054 mm minimum. Needs to move up.

Pitch: desired 639 urad up +/- 100urads. Error 275urads  (angle set at 89deg, 57', 48" = 0urads) optic needs to pitch down.I used an iris to prevent AR side clipping

Yaw: desired 270deg +/- 100urads. Error 1.0 mrads urads. ISI/SUS needs to rotate ccw

Looks like some HEPI tweaks are next and another round of measurements

7:30-12:25 Heading to Mid Y - Jodi
8:05 --> PSL Check List (OK)
8:25 --> Ace portable toilets on site for maintenance
8:52-9:20 Working at End X – Aaron
9:20-12:00 Heading to End Y (chassis installation) – Aaron
9:31-12:30 Going to End Y (Cleaning/Organizing) - Karen
9:48-10:29 Performing work on GV-6(PT-124) in LVEA - Kyle
10:12-11:00 Going to End X to do HEPI work – Hugh
10:00-10:15 CDs work(reverted h1 susitmy model back to original/h1 iscey model rebuilt and restarted) - Dave
10:15-12:06 Running cables by BSC2/BSC3 (LVEA) - Filiberto
11:04-11:39 Doing measurements at End X - Keita 
11:10-12:30 ITMs work (LVEA)- Betsy/Travis
11:31--> LN2 delivery to CP6 (Mid X) – Praxiar
11:36--> Vendor delivery on site (Water)
13:01-    HEPI work on HAM4 – Hugh
13:19-    Back to Mid Y – Jodi
13:26-    Going to End Y to work on illuminator – Filiberto
13:47-16:00 Heading to End Y (electronics testing) - Jax
14:59-     LVEA transitioned to Laser Hazard

Dave B., Patrick T.

122,128 channels are now monitored.

The list is in /ligo/lho/data/conlog/h1/output_pv_list/monitored_pv_list_2014mar04-14_44.txt.

Fil, Thomas

Since it was Tuesday maintenance day, I thought it would be a good time to try to improve/fix the ITM optical levers:

- The sign conventions for positive and negative directions now fully match suspension bias sliders. This solves the negative sign difference in Keita's ALOG-10331 between the OpLev and his coordinate system.  I will plan on doing this for the ETMs as well, but with the new damping loops that are initiated on the lower stage, I'm going to talk to Stefan before making a change.

- Arnaud's ALOG-10426 pointed out that the noise floor at high frequency (above 100Hz) for ITMY was different from ITMX and ETMX by two orders of magnitude.  I let him know that the main difference in electronics is the whitening/anti-whitening chain not being activated for ITMY because we don't have enough binary daughter boards for all the optical levers on site (they are being ordered by Mohana).  Since we are in need of this optical lever to be in its final configuration, Fil created a jumper plug to recreate the daughter boards to activate two levels of whitening to make all test mass OptLevs match.

Figure 1 shows that improvement of the noise floor of ITMY so that it's even better than ITMX now.

Figure 2 shows that we did activate 2 levels of 1:10 whitening.

Today's restarts tested my new model restart logger. Here are the contents of the file /opt/rtcds/lho/h1/data/startlog/2014/03/04/2014_03_04_model_start.log

2014_03_04 09:53 h1susitmy

2014_03_04 09:58 h1iscey

2014_03_04 11:46 h1isibs

2014_03_04 12:24 h1isiitmy

2014_03_04 12:25 h1isietmy

2014_03_04 12:44 h1lsc

2014_03_04 12:47 h1pemmx

2014_03_04 12:54 h1isiitmx

2014_03_04 13:10 h1isietmx

13:11PST performed DAQ restart. Was not a clean restart, the following frontends required a restart of their mx data stream: susauxex, susex, pemmx, susauxey, iscey, sush2b, sush56, susauxb123, susauxh34, susauxh56. As normal, h1psl DAQ flags went red/green during these resyncs.

DAQ restart was needed due to new models on: h1susitmy, h1iscey, h1isibs, h1isiitmy, hisietmx, h1lsc, h1isiitmx, h1isietmx.

DMT broadcaster was reconfigured to add one new channel: H1:PSL-PERISCOPE_A_DC_POWERMON

The models (master and local models), scripts and MEDM screens have been updated to support new changes made by the Stanford crew (see update list DCC T1400012).

Everything went well and has been committed.

J. Kissel, A. Pele

Following the same procedure outlined in LHO aLOGs 9453 and 9079, Arnaud and I balanced the coils on the PUM stage of H1 SUS ETMX. The final balanced gains in the L2_COILOUTF bank are

H1 SUS ETMX
Channel     Balanced COILOUTF Gain
L2 UL            +1.034
L2 LL            -1.014
L2 UR            -0.986
L2 LR            +0.966

The precision to which we could balance the coils was limited by the day-time ground motion (we saw an almost instantaneous loss in SNR once the day-time 1-10 [Hz] noise increased around 8:30a PT), but we believe the obtained values are good to within +/- 0.5%.

This balancing has reduced the L3 P and Y caused by a L2 pringle excitation at 4 [Hz] by
   DOF                  Reduction Factor @ 4.0 [Hz]
    P                          > 6.0      (peak below the noise, and totally incoherent)
    Y                          > 7.3      (peak below the noise, and only ~60% coherent)
The first attachment shows the result from which these values were obtained, comparing the optical lever ASD at 4 [Hz] driven from L2 at the same amplitude for both balanced and unbalanced configurations.