Green arm transmission was first found on the Swiss cheese baffle while scanning PR3.

After centering the beam on the POP hole in the baffle (PIT was already good, YAW was off by 86urad), we looked inside HAM1 and found that the beam was already coming in that chamber. The beam was hitting somewhere on the green/IR separator M10, and some scattering or maybe specular reflection was hitting the beam duct of IR POP path, but nothing seemed to be hitting the green steering mirror M11.

Turning PR3 by +10urad in YAW and the beam was already blocked on the mirror holder of M11.

Turning PR3 by -10urad in YAW and the beam was nowhere to be found in HAM1, and we couldn't identify where the beam is blocked in HAM2, but it kind of seems from one of the GigE cameras that the beam might be blocked by one of the MC towers.

See attached if this helps.

Right now PR3 is set to the "neutral" position where the beam is centered in the baffle hole, but probably that's not the right thing to do (because the space between MC1 and MC3 tower gives us a tight aperture in YAW). We'll go in HAM1 tomorrow to find a right solution.

I went back to the end station to look into why the frequency comparator readback has not been reliable.  There was 1MHz oscillation on the readout of the PD that is similar in size to our beatnote, which was confusing the frequency comparator.  The oscillation goes away when the noise eater is on, and the frequency readback works well.  For now I have left it on, although this isn't a long term solution.

In alog 6669 I came to the opposite conclusion, that the nosie eater had to be off to avoid oscillations at 1 MHz that confuse the frequency comparator. A high pass in the path to the frequency comparator might take care of the problem.

Cyrus created a new EPICS gateway between the H1-AUX and H1-FE VLANS to permit the DAQ EDCU to acquire the new PSL Centroid EPICS channels created by Chris W. The new gateway is called h1aux-h1fe (client on h1aux, server on h1fe). The DAQ EDCU quickly connected to the new channels and became GREEN.

Today we were frought with more fiber pulling issues.  After sorting user errors with the profile math yesterday, today the fiber puller was cranky.  The latest problem this afternoon was that a piece of the mechanics on the bottom stage of the puller pulled out of place (a problem that has been seen before).  It will (again) take a few hours of their time to fix tomorrow.

Meanwhile at EY, Jason and I repositioned the UIM and PUM in prep for the rewelding scheduled for later this week.  When we went to position the test mass, Jason discovered that the HR return beam was very faint and the autocollimator could not get a reading off of it.  LLO reported this finding when they did their ETM.  We will pull the First Contact thin alignment sheet down a bit and try see if that improves the visability.  Otherwise, we may entertain the idea of sighting off of the AR surface for pointing which has a much better return for the 670nm autocol beam.

Oh, and the cookie cutter for repositioning the ETMy QUAD upper structure on the ISI appears to have been machined incorrectly.  I have time to fix it.

Fire Department on site doing maintenance
Installation and alignment of the GigE cameras at the HAM2 and HAM3 spools – Kiwamu
Centering SR2 BOSEMs at LVEA – Jeff B.
Baffle work at LVEA West bay – Mitchell
Electrician working at H1 electronics room
Work at End X – Sheila/Koji/Alexas
Turning Off aLOG, SVN, and awiki services due to hardware problems – Jonathan
Work on H1 PSL diode room – R. Savage
Cable pulling from Electronics room to HAM2 – Luis
aLOG, SVN, and awiki services have been turned ON – Jonathan
Remove the HAM1 viewport covers and/or camera cans – Keita/Kiwamu/Sheila/Koji/Alexa
Soft-close GV20  at End X- Kyle
Removing yellow cover from viewports on HAM1, HAM2 and HAM3 – Stefan
Fix to the ETMX, ETMXY, TMSX and TMSY models – Jeff K.
Hardware cabling at End X - Richard

In anticipation of some new changes to the ASC_MASTER library part, I updated it to the latest version from LLO. This includes pitch and yaw outputs for RM1,RM2,OM1,OM2. I updated our h1asc.mdl accordingly, recompiled and restarted it. SVN version number 6759.

Back on 23 December, Keita found the need to tilt the HEPI to pitch the TMS.  Attached is a plot showing the T240 signal going back 30 days from now.  The time keita tilted the HEPI is pretty obvious in the middle of the trends when tilted axes of the T240s are affected.  Much of the period since 23 Dec has the ISI off (tripped from T240 saturations) and so not the source of the increase in these T240 signals.

As I've logged before, the ETMX ISI has not managed to stay engaged for more than a few hours since this time.  Notice too on these trends, the signals with the largest amplification has a regular hit of the rail.  The second plot I've attached is a single channel of 15 days.  Notice the rail hit every 24 hours; this is to the minute as best I can tell from a 15 day dv trend.  I am suspicious that this is real given the periodicity.

Finally, the last plot zooms in to 8 days of this channel and I've added a channel indicating the HEPI tilt.  Notice in the middle of the plot where on 2 & 3 Jan I'm mucking about with tilts and ISI.  The noise of the T240 is reduced when there is no tilt applied.

J. Kissel, T. Vo, R. McCarthy

Both sites have simultaneously discovered that the optical lever signal wiring has changed between version 5 and version 6 of the ETM System Wiring Diagram, D1002741, specifically page 4. However, since we're just now turning on the EM optical levers (whose signal installation required the change), we discovered that the front-end Simulink model is still wired according version 5 as cables were plugged in according to version 6. Note that the drawing changes were made back in July of 2013, as a part of resolving Integration Issue 78, but this week is the first time the changes have been exposed to installation reality at either site. 

As such, I have re-wired the following models:
${userapps}/sus/h1/models/
h1susetmx.mdl
h1susetmy.mdl
h1sustmsx.mdl
h1sustmsy.mdl
such that, in the ETM models:
(1) Remove ADC1 from the top-level, since it no longer used in the ETM control models.
(2) Change the From tag for the optical lever signals from "ADC1_2_QUAD" to "ADC0_2_QUAD," such that it receives signals from ADC0.
(3) Re-selected ADC0 channels 0_24, 0_25, 0_26, 0_27, which are Quadrants A, B, C, D on D1002741, and Segments 1, 2, 3, and 4 in the QUAD simulink Library part, respectively.
and in the TMS models:
(1) From the ADC0_2_TMTS From tag, re-selected ADC0 channels 0_28 and 0_29 for M1 RT and M1 SD, respectively.

Richard has now swapped the analog cabling accordingly, such that now both analog and digital match version 6.

Note, the naively annoying signal shuffling that affects and separates the TMTS OSEM signals was done to preserve the last two channels on the ADC0 as open/spare required for the standard DAC and ADC duotone signals of every IO chassis.

All top-level models (which is all that was affected by these changes) have been committed to the userapps repo as of this entry.

H1 SUS ETMX AND H1 SUS TMSX have had their damping restored, and their alignment offsets restored to what they were just before the reboot. 

As the SEI/SUS watchdog system still stands, taking down the suspension models trips the HEPI and ISI, so I've restored the ISI to damping, and left HEPI untripped but requesting no actuation, since I don't know the state of these chamber's commissioning. I have not restored the 12000 nrad offset that Keita has installed to fix the differential alignment between ETMX and TMSX (see LHO aLOG 9064) that's need to lock the arm cavity on green (see LHO aLOG 9127) because he's put it in the hidden offset of the RY IPS blend filter bank, and I'm not sure whether position loops are functional. This should be moved to the DC BIAS location, and position loops should be run. I'll speak with Keita and the SEI team.

The aLOG is being turned off to examine possible hardware issues.

When aligning the X arm I thought that the green beam is too small on ITMX and ETMX, but when I actually looked at the data, the beam size on ITMX is not bad.

I adjusted the TMSX sliders to maximize one of the baffle PDs, moved TMSX in yaw such that the power on the PD drops, and assessed the beam size assuming that the beam is sufficiently smaller than the beam radius.

Attached plot shows that 4.4urad TMSX slider change in YAW makes one of the baffle PDs to drop from the peak by about half (.125/.240 = 0.521 to be more precise). From alog 9126 we know that the slider calibration for YAW is 1.07 [urad/urad], so the beam displacement is x=1.07E-6*4.4urad*4E3m=18.8mm.

exp(-2x^2/w^2) = 0.125/0.240= 0.521, x=18.8mm, therefore:

w=sqrt(-2/ln(0.521))*x=32.9mm.

I don't claim that the measurement has a mm accuracy, though, because I don't know the baffle PD size.

Sheila and Alexa reported issues seeing Beckhoff channels from the control room workstations, so I restarted the h1slow-cds EPICS gateway process.  This appears to have corrected the problem.

Alexa and I restarted h1ecatx1 after we got a run time sytem not found error (from PLC2 or run time 2)  

Valved-in IP1,2,5, and 6*Dumped GV7's unpumped gate annulus volume into pump cart*Valved-out YBM turbo*Opened GV7*Valved-in IP12*Dumped GV20's unpumped gate annulus volume into pump cart*Valved-out X-end turbo*opened GV20*Dumped GV5's unpumped gate annulus volume into pump cart*Opened GV5

[Stefan, Kiwamu]

We adjusted the phase difference (e.g. LSC-REFL_A_RF9_PHASE_D) of all the REFL and POP demodulators except for a WFS channel which showed suspiciously small signals.

Observations on the I/Q relations:

We discovered that the amplitude imbalance between any pair of I and Q were good and were typically less than 0.5%.  Also, the extra imbalance that can be introduced by changing the whitening settings are almost comparable to 0.5% and we concluded that it was pointless to correct the amplitude imbalance at this point unless the whitening settings are fixed. Therefore we didn't attempt to correct them this time. On the other hand, the phase difference was not as sensitive as the amplitude imbalance to the whitening settings. They were found to be typically off by a couple of degrees from 90 in the first place, while changing the whitening settings didn't rorate them more than 1 degree. This is the background story of why we ended up adjusting only the phase differences.

One demod board doesn't look healthy:

In the process of the adjustment, we found that channel 4 of the WFS REFL_B_RF9 demod board (SN:S1000994) displayed too small signals in both I and Q by a factor of 2-ish in their amplitudes compared with the rest of three channels. We must pull this board out of the rack and take a close look in the EE shop.

Adjustment of the phase difference:

We used the same technique as Anamaria did at LLO (see LLO 6829). The RF frequency was set apart by 40-50 Hz from the LO frequency in each demodulator by using an IFR RF source. The RF level was at -40 dBm for the LSC demods and -41 dBm for the WFS demods. None of the whitening stages were engaged. The whitening gains were simply set to be their maximum (i.e. 45 dB) during the measurement. The belows are the results:

* * * in-vac 1f

H1:LSC-POP_A_RF9_PHASE_D       87.30
H1:LSC-POP_A_RF45_PHASE_D      92.93
H1:LSC-REFL_A_RF9_PHASE_D      88.63
H1:LSC-REFL_A_RF45_PHASE_D     92.98

* * * in-air 1f

H1:LSC-POPAIR_A_RF9_PHASE_D    87.78
H1:LSC-POPAIR_A_RF45_PHASE_D   92.95
H1:LSC-REFLAIR_A_RF9_PHASE_D   88.27
H1:LSC-REFLAIR_A_RF45_PHASE_D  92.98

* * * 2f and 3f

H1:LSC-POPAIR_B_RF18_PHASE_D   89.17
H1:LSC-POPAIR_B_RF90_PHASE_D   91.05
H1:LSC-REFLAIR_B_RF27_PHASE_D  91.39
H1:LSC-REFLAIR_B_RF135_PHASE_D 84.49
 

* * * WFS REFL 9

H1:ASC-REFL_A_RF9_SEG1_PHASE_D 88.28
H1:ASC-REFL_A_RF9_SEG2_PHASE_D 88.34
H1:ASC-REFL_A_RF9_SEG3_PHASE_D 88.55
H1:ASC-REFL_A_RF9_SEG4_PHASE_D 88.55
H1:ASC-REFL_B_RF9_SEG1_PHASE_D 89.17
H1:ASC-REFL_B_RF9_SEG2_PHASE_D 88.32
H1:ASC-REFL_B_RF9_SEG3_PHASE_D 88.64
H1:ASC-REFL_B_RF9_SEG4_PHASE_D 0
 

* * * WFS REFL 45

H1:ASC-REFL_A_RF45_SEG1_PHASE_D 91.96
H1:ASC-REFL_A_RF45_SEG2_PHASE_D 93.15
H1:ASC-REFL_A_RF45_SEG3_PHASE_D 92.37
H1:ASC-REFL_A_RF45_SEG4_PHASE_D 93.18
H1:ASC-REFL_B_RF45_SEG1_PHASE_D 92.80
H1:ASC-REFL_B_RF45_SEG2_PHASE_D 91.65
H1:ASC-REFL_B_RF45_SEG3_PHASE_D 92.88
H1:ASC-REFL_B_RF45_SEG4_PHASE_D 93.00
 

References: D1201036 (BSC9 ACB assy) and D1200314 (BSC3)

Gerardo read the distances between the baffle diodes off of CAD drawings for me (see the attached cartoon). 

ITM baffle PD1-PD4 separation is 11.3" over 4km (72 urad) both horizontally and vertically. For ETM the number is 11.8", so it's 75 urad.

Don't know why the patterns are different for ETM and ITM, but using these we can calibrate TMSX, ITMX and ETMX bias sliders. Note the factor of 2 between TMS and mirrors, this is because TMS moves with the beam but mirrors don't.

Calibration of ETMX is somewhat suspect (at 10urad level) because of the fact that the position loop of EX ISI got accidentally off before I did ETMX adjustment.

Summary: Green injection hits the center of ITMX, comes back to the center of ETMX, and then back again to the center of ITMX. The alignment is good, with one caveat that HEPI should be tilted significantly in  PIT to help TMS. Since EX PIT is unaffected by the HEPI, we're using EX sus bias to point it down by 330 urad.

1. Green beam from TMSX to ITMY

After Kyle opened the GVs we started scanning TMS to find the green beam on ITMX baffle diodes. Somehow PD4 amplifier was busted so we reconnected PD4 to PD3  amplifier.

At first TMSX was pointing up too much, and I had to give HEPI a PIT (RY) offset of -12000 counts to H1:HPI-ETMX_BLND_IPS_RY_OFFSET with a gain of 1. HEPI loops were all open, so that just gave a DC offset to the HEPI angle. After that treatment, we were able to maximize the output of three baffle diodes using the following offsets for TMS bias:

See E1300634, figures 12 and 13, for the diode layout. PD1 and PD4 are two diagonal ones around the baffle hole, PD2 and PD3 are far from the mirror. "Center" is the mean of PD1 and PD4 and should be close to the real center of the optic.

Baffle diode channel names are H1:AOS-ITMX_BAFFLEPD_1_POWER etc., but they are not trended as of now. Also note that H1:AOS-ITMX_BAFFLEPD_3_POWER is actually reading PD4.

Transimpedance for the PDs were set to 20 kOhm, and when maximized the outputs were about 2.5V for PD2 and PD3, and about 2.3V for PD1.