K . Venkateswara

I installed two temperature sensors, one on the BRS vacuum can and one on the ground T240 at EX. They are temporarily being read on the PEM_Tiltmeter_T and PEM_Tiltmeter_Y channels respectively.

H1:PEM-EX_TILT_VEA_FLOOR_T_MON   =   BRS temperature sensor

H1:PEM-EX_TILT_VEA_FLOOR_Y_MON   =   GND_T240 temperature sensor

The temperature sensors consist of a 10k-ohm thermistor bridge powered by a 9V battery each. There is no amplification, so the calibration should be ~ 1/2 * beta / (10k) * 9V = 0.2 Volts / Kelvin , where beta value for the 10k thermistor is roughly 450 ohms/Kelvin.

J. Kissel, J. Warner, E. Merilh

I've updated the QUAD_MASTER.mdl, BSFM_MASTER.mdl, and HLTS_MASTER.mdl front-end library parts to obtain the changes Stuart has installed (see LLO aLOG 15437) in order complete ECRs E1400295 and E1400434, which have been tracked with II 969 -- "Changing Optical Lever DAQ Channels," and II 921 -- "Removal of old Guardian Parts," respectively, (governed by Work Permit #4932). This affects all core optics with optical levers, i.e. 
H1SUSPR3, H1SUSSR3, H1SUSBS, H1SUSITMX, H1SUSITMY, H1SUSETMX, H1SUSETMY.

This should close out the above mentioned ECRs and Integration Issues. Thanks to Jim and Ed for their help.

In doing so, we had to 
- svn up /opt/rtcds/userapps/release/sus/common/models/
- Request all affected SUS guardians to SAFE
- Capture new safe.snaps for all affected SUS (not necessary, but seems to be good practice)
- Request all affected SEI guardians to OFFLINE
- Recompile the model / front-end code,
      make [h1suspr3, h1sussr3, h1susbs, h1susitmx, h1susitmy, h1susetmx, h1susetmy]
- Reinstall the model / front-end code,
      make install-[h1suspr3, h1sussr3, h1susbs, h1susitmx, h1susitmy, h1susetmx, h1susetmy]
- Restart the model / front-end code,
      ssh [h1sush2a, h1sush56, h1susb123, h1susex, h1susey]
      start[h1suspr3, h1sussr3, h1susbs, h1susitmx, h1susitmy, h1susetmx, h1susetmy]
- Request all affected SUS guardians to ALIGNED
- Request all affected SEI guardians to FULLY_ISOLATED / HIGH_ISOLATED*

Bringing back up the SEI platforms was more challenging than expected, but I'll write a separate aLOG on that since it'll be focused on SEI issues.

Beam tube modeling gives higher frequency resonances than are measured, suggesting that the fixed supports are more compliant than in the model. I had accelerometers and shakers nearby so I could easily measure the displacement with height. Figure 1 shows the quasi-static displacement with height for a 5 Hz injection (below the resonances). The results suggest that the insulation may be the softest part of the spring: most of the increase in displacement with height happens across the insulation and the piece that rests on it, as if the piece were rocking on the insulation.

Robert, Fabrice

Nic, Jeff, Dave

Last Tuesday the h1lsc model was compiled against RCG2.8.5 (modification to IPC DARM to the SUS models). My bad, I forgot we had downgraded this model to RCG2.8.3 on 09 September 2014 to fix the channel shifting of slow data in the DAQ (alog link below)

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=13835

The problem was rediscovered by Nic yesterday, as the saying goes, its deja vue all over again.

I recompiled h1lsc against RCG2.8.3 this morning. At Jeff's request I updated the safe.snap file before restarting. The INI file was modified by the recompile. There were 12 testpoints open at the restart, and they remained open after the model got going again. I manually cleared them.

A DAQ restart was made soon after, which also resynced the modified SUS models.

I tested the slow channels were fixed by comparing some slow channels on StripTool (channel access client) against the same channels on dataviewer (nds client).

Added 75ml of water to the chiller.

Initial attempts to take undamped TFs on ITMX & ITMY exhibited rung up P & R modes (see LHO aLOG entry 14653). For the next attempt, fine tuning of excitation amplitudes was necessary to avoid ringing up these modes.

Phase 3b (in-vacuum) undamped TF measurements have been taken for ITMX & ITMY (QUAD) suspensions as follows:-  

- ITMX M0-M0 undamped results (2014-10-30_0700_H1SUSITMX_M0_ALL_TFs.pdf)
- ITMX R0-R0 undamped results (2014-10-30_0700_H1SUSITMX_R0_ALL_TFs.pdf)
- ITMY M0-M0 undamped results (2014-10-28_1200_H1SUSITMY_M0_ALL_TFs.pdf)
- ITMY R0-R0 undamped results (2014-10-28_1200_H1SUSITMY_R0_ALL_TFs.pdf)

ISI Status: ISI's damped and FULLY_ISOLATED via Guardian.

ITMX & ITMY undamped TFs above have been compared with other similar QUADs at the same phase of testing (allquads_2014-10-30_AllQUADS_Doff_Phase3b_ALL_ZOOMED_TFs.pdf). The plot key is as follows:-

Blue Trace = Model Prediction (fiber/thincp).
Orange Trace = L1 ITMX (fiber 2013−09−04), Phase 3b.
Black Trace = L1 ITMY (fiber 2013−09−05), Phase 3b.
Magenta Trace = H1 ITMY (fiber 2014−10−28), Phase 3b.
Cyan Trace = H1 ITMX (fiber 2014−10−30), Phase 3b.

Summary:

M0-M0, main chain TFs are a very good fit to the model, for all DOFs, with only some minor cross-couplings from P2V.

R0-R0, reaction chain TFs agree with the model predictions and are consistent with similar QUADs. The largest deviation from the model can be seen with the ~1.45 Hz P mode, a consequence of the harness routing stiffening the suspension, seen before. Some minor cross-couplings are also present: from P2L, P2R, and P2V only for ITMY. Damped TFs should be taken to verify that damping loops suppress these cross-couplings.

All data, scripts and plots have been committed to the sus svn as of this entry.

With approval from Jeff K, I am about to begin updating the EPICS settings controlling the ODC (state vector) for the SUS subsystem.
These changes include:

- Update bit strings to latest configuration, including OPLEV damping names
- Update bitmasks to not include LOCK state checks in ODC summary bits
- Update and commit safe.snap files to capture the above changes

These changes will not affect any EPICS settings not under the 'H1:SUS-{optic}_ODC' prefix.

no restarts reported

As an exercise to test out the OMC --> LSC signal path, I locked the simple Michelson using the OMC-DCPD_SUM signal.  With MICH locked on a dark fringe with a 35 count offset, I measured the DCPD-to-MICH transfer function.  The DCPD sum was a factor of ~4 smaller and off by 180deg at low frequency, so I loaded "-4" into the LSC input matrix (OMC DC --> MICH) and zeroed the ASAIR_RF45 element.  The lock was very smooth, with about 2x more gain than the vanilla MICH loop.  (I found the guardian-set gain the  MICH_DARK_LOCKED state was about 3x smaller than maybe it should have been, so I increased it from -500 to -1400 before the handoff.  After the handoff I reduced the gain to -700. The UGF with these settings was ~7.5Hz, roughly aligned with the peak of the phase bubble.)

Comparisons of the OLTF in both states (with the gain settings described above) are attached, so are noise spectra for the error and control signals.  In both plots the references are the RF lock, current signals are the DC lock.

Alexa, Evan, Sheila, Jeff, Nic, Lisa

The plan for tonight was to try again the CARM offset reduction with the DRMI locked on 3f as it was done  a few nights ago . 

However, sadly, we couldn't really stably lock the arms on green by engaging ALS DIFF (feed-back to the ETMs). 

Nothing was (at least intentionally) changed with respect to the "nominal" configuration which has worked in the past. 

In the process of collecting and analyzing several lock losses, we identified the following list of problems/action items:

 * L2P for ETMY is significantly worse than for ETMX, we should fix this: as soon as the differential feed-back to the ETMs is engaged, the ETMY green light fluctuates consistently with PIT fluctuations as seen by the optical lever. This effect was really bad in the afternoon (30% power fluctuations; it got somehow better later in the evening); 

 * ringing up of the 13 Hz ETMY roll mode (again, see Kiwamu's entry): Nic tried to damp this mode by using optical lever PIT as error signal and pushing on L2 PIT, but that didn't work. We will try tomorrow to use the  LLO strategy  by using ALS DIFF;

 * at least once we lose lock because of a 3Hz oscillation in the ESD drive (we should remeasure the cross over L1/L3).

While trying to debug the ALS, we did some work on the DRMI to investigate the tricky demod phase business (see  Evan's entry). 

Nic and I briefly entertained the idea of going out to the end stations to optimize the gain and whitening on the ETM oplevs, but decided (based on the attached spectra of the segments) that it was good enough for today's oplev work.

Alexa, Sheila, Lisa, Evan

Today we looked a bit further into the demodulation issues we've been having with the DRMI sensing matrices (see 14792).

Using the same technique as described in LHO#14792, we measured the response of REFLAIR_A and REFLAIR_B (along with REFL_A) while driving PR2 and SR2.

We ran at 10 W into the IMC, with no ND filter on any of the diodes. Excitations were 131.7 Hz and 6000 counts on PR2, and 183.8 Hz and 6000 counts on SR2. At one point, we also tried exciting PR2 at 211.7 just to make sure our results were the same (and they were).

While monitoring the PSDs of the RF-demodulated diode signals, we tuned the phases as follows:

• RF45 was tuned to minimize the amount of SRCL signal in Q
• RF9 was tuned to minimize the amount of PRCL signal in Q
• We did not retune RF27 or RF135.

The attached plot shows the RF-demodulated diode signals after this retuning. Our conclusions are as follows:

• SRCL and PRCL are nearly orthogonal in REFLAIR_B_RF135.
• For the remaining diodes, SRCL and PRCL are not as orthogonal, but nonetheless cannot both be fully put into the I phase.

The DTT file for this measurement is at /ligo/home/evan.hall/Public/2014/11/REFL_Tuning/REFL_Tuning_Spectra.xml.

Alexa made sure that there was no clipping or any other funny business with REFLAIR_B.

We briefly tried to take a measurement at a lower input power, but could not keep DRMI locked.

For reference, the original demod phases are as follows:

• REFLAIR_A_RF45: 143°
• REFL_A_RF45: −5°
• REFLAIR_A_RF9: 93°
• REFL_A_RF9: 62°

Dave [WP#4929] new models for h1calex, h1caley. Same functionality, split code into a common library part. May install h1calcs on h1oaf0 if the specific_cpu assignments can be verified for this front end. DAQ restart is required.

Dave: Reconfigure EDCU for latest Beckhoff and resync to guardian. Restart DAQ.

Jeff K, Stuart A: possible SUS model optlev changes, DAQ restart required.

Dave: recompile h1lsc against older version of RCG to fix slow-data-channel-offset-in-daq problem which was reintroduced last week

No other work planned.

They are not 'prepared' yet but that is but a moment.  So this uses TF data from 4 Sept 2013 but with the correct Local <--> Cartesian matrices.  Additionally, these are Hugo's Generic Controllers in use already on HAMs 4 5 & 6; we'd like to use these where ever we can.  Otherwise I attach them here if you wish to look at them.  A few of the dofs have phase margins less than 30; but, our problem at EndX had only 20 degrees of margin.

I plan to 'prepare', load , and test them tomorrow morning.

9:00 Bubba to LVEA measuring cleanrooms

~10:58 Rai and Kyle to EY removing ionizer setup

12:00 Rai and Kyle back from EY

1:00 Cris and Karen to MX and MY respectively

1:45 Karen leaving MY

Alastair

The flipper mask holders are installed on the X and Y tables.  Both are cables up and working using a 'caput' command.  At the moment they won't work using the MEDM screen since this requires checking the state of the flipper (up/down) using sensors that are not yet on the table.

Final outstanding intstall work is :  X-table needs 1 flipper sensor.  Y-table needs 2 flipper sensors, FLIR camera and baffles around PDs.

Rana, Alexa, Sheila, Peter, Evan

Given last night's strange behavior from REFLAIR_B, we wanted to check the RF powers coming out the BBPD and going into the ISC rack.

With DRMI locked (on 1f, and then on 3f), we used the HP4395A to take an RF spectrum of the "direct" output of the REFLAIR_B diplexer board. This should be the raw RF signal out of REFLAIR_B, with 12 dB of attenuation from a coupler inside the diplexer.

The spectra (adjusted for the 12 dB coupler) are attached.

For 27 MHz, the power into the diplexer is -41 dBm. Using the diplexer schematic (D1300989), this should give -23 dBm at the diplexer's 3x output, which is well below the compression point of the amplifier (ZHL-500HLN+; 1 dB comprsesion occurs at +16 dBm). Similarly, for the 15x output we expect -13 dBm.

The analogous LLO measurement is at LLO#10494.