With the addition of the WFS/auto-centering/tidal the CPU cycles in end station isc models have gradually increased to the point where we saw IPC errors in the lsc of ~1000err/sec from ex and ~10000err/sec from ey. The ey problem was compounded by adding the temporary oscillators last Wed. This mainly effects the transmitted red power which is sent to to the corner for locking. We removed the temporary oscillators, the other 2 oscillators we never used, as well as the WFS path to the input PTZs. This reduced the IPC errors as seen by the lsc to 1-2err/sec (both ex and ey). There are still ipc errors from the lsc to the sus (DARM_ERR) around 10err/sec (unchanged).

The DAQ did not restart cleanly after the evening's h1iscey and h1iscex model changes. After checking for duplicate channels in the DAQ configuration (of which there were none) I manually restarted monit on h1dc0. The DAQ started cleanly this time.

I did some tests on the bsc chambers this morning 

• closed stage 1 and 2 Rz controls on ETMX ETMY ITMX ITMY with 750mHz blend filters ("T750mHz" in FM2) - first and second screenshots-

They have been left on during the day (from ~19:00 UTC) to eventually get some offline data. The oplev yaw see some minor improvement for ITMx and ETMx, but nothing for the other two chambers (first screenshot). The references are without the Rz loops running. The second screenshot is for the cps afficionados. 

• open st2 rz and reduced the stage 1 rz blend to 45mHz to observe the z->rz coupling -third screenshot-

the references are with st1 rz closed at 750mHz. When the blend is low -45mHz-, st2 gs13 signal is better between 0.2Hz and 5Hz but worse below 0.2Hz. The st1 cps see a large relative motion with the ground at low frequencies. 

I didn't have a chance to try the last configuration with the subtraction path engaged.

The dtt templates are under /ligo/svncommon/SeiSVN/seismic/BSC-ISI/H1/{chamber}/Data/Spectra/Isolated

This entry corrects log 16052. The plots there were given the wrong DOF titles. While at it, I added plots comparing stage 1 to stage 2 TFs. The model matches well around the resonances here, but has the wrong slope at higher frequencies.

The model is located on the svn at

/ligo/svncommon/SeiSVN/seismic/BSC-ISI/Common/BSC_ISI_Model/N4SID_Model/L1BS/BuildFullL1BSmodel.m

To compare the model to data, run

/ligo/svncommon/SeiSVN/seismic/BSC-ISI/Common/BSC_ISI_Model/N4SID_Model/L1BS/CompareModel_to_data.m

J. Kissel, H. Radkins, J. Warner, A. Pele

Here's a recap of the the week's progress, contrasted against last week's to-do list; revising it for the next week or two. Arnaud's back to LLO tomorrow, Krishna's in for next week.

Improve The Chamber Noise Performance:  
     All Chambers                                                 Benefit to IFO
     - ST 01 L4C Feed Forward (all 6 DOFs),             improve 1 to 10 [Hz] performance -- No progress yet
DONE - Sensor correction gain matching (all 3 DOFs),    improve 0.08 to 3 [Hz] performance (see LHO aLOG 16208)
         - Turned into "Investigate factor-of-2 problem with Corner Station STS B's X Channel" (see LHO aLOG 16237)
     - Assess whether switching to differential pressure affects platform noise performance -- suddenly interesting, may impact sub-0.1 [Hz] Yaw (see LHO aLOG 16231)
         - Measure HEPI Pump Servo Plant
         - Tune Pump Servo PID loop
         - Differential Pump Pressure signals are noisy possibly from poor electrical grounding, fix it if still there after loop tuning

     BSCs Only
     - Z to RZ subtraction,                            reduce BSC optic's yaw below 0.08 [Hz]  
            This has turned into "Close RZ loops on Stage 1 and Stage 2 with high frequency blend filters" but seems to have little to no improvement. Continue Assessment.
     - Discuss / Assess closing the rest of ST2 isolation loops
     - Assess performance of loops with GS13s in low gain vs. high gain (are we ADC noise limited?)
     - Implement Slow MICH,                        reduce MICH velocity, improving lock acquisition -- No progress; waiting for Ryan DeRosa
DONE - Finish ITM HEPI Z to RX/RY Tilt Decoupling,     reduce BSC optic's yaw below 0.08 [Hz] (see LHO aLOG 16118)

     HAMs Only
DONE - HAMs 2,3,4,5 Isolation Loop Gain Increase       improve 0.5 [Hz] to 20 [Hz] performance (see LHO aLOG 16214)
     - Continue HAM3 0.6 [Hz] feature investigation        improve 0.6 [Hz] performance
            No progress on *solving* the problem, but some investigation on finding a better compromise (see LHO aLOG 16196

Improve the Maintainability / Extensibility:
     - BSC-ISI Noise Budget Model -- Good Progress; see G1500081
     - HAM-ISI Noise Budget Model -- No progress yet; sort of waiting for BSC-ISI budget to be more developed
     - HEPI Noise Budget Model -- No progress yet
     - Assess guardian vs. watchdog robustness of bringing all chambers to OFFLINE from FULLY_ISOLATED -- No progress
     - Put MATCH OUTPUT channels on Sensor Correction overview screen -- No progress
DONE - Storing more than just RZ on HEPI alignment (see LHO aLOG 16207, LHO aLOG 16191)
     - Switch ETMX to using differential pressure signal
     - Include closing ST1 and ST2 RZ loops into guardian
     - Include gain switching on all Guardians
     - Get ISI system under SDF system configuration control
DONE - Get HPI system under SDF system configuration control (see LHO aLOG 16217)
DONE - Install DeRosa filters into NXT blend filter banks, such that blend switching may eventually work (see LHO aLOG 16200)
     - Figure out how to make blend switching code work with multi-bank filters

Relegated to installation AFTER 2 hour lock:
     - Hook IOP SWWD signals up to ISI USER watchdog
     - Install HEPI saturable integrators
     - Remove HEPI / ST0 L4C Sensor Correction path from ISI models

8:48 Keita to EX working on ISCTEX

9:01 Keita done

9:03 Jim and Arnaud to MSR and LVEA looking at cabling

9:05 Gerardo to LVEA decoupling vacuum pump

9:11 Sudarshan and Fil to LVEA working on PEM mics

9:27 Gerardo done

10:30 Manny and Essence to MY 3IFO inventory

10:36 Sudarshan and Fil done

J. Kissel, H. Radkins

We'll fill out with more plots, data, and information later, but we've found that the newly installed differential pressure readout in the corner station HEPI pumps is coherent with noise in the BSC HPI L4Cs between 0.1 and 1 [Hz] in Z, and 0.01 - 0.1 [Hz] in RZ. I attach results for the Beam Splitter's tank.

**Edit -- Page Three had terribly confusing labels, I've now fixed the plot to reflect the information correctly -- its the rotational DOFs, which are, of course, in [rad/rtHz].

Jeff wanted me to see if I could find some cavity signals to assess the performance of the corner station ISI's after my work on the HAM's on Tuesday. The commissioners gave us a bunch of channels to look at, but it looks like there haven't been any DRMI lock stretches long enough for us to get good spectra. I've attached trends of the 4 channels we want to look at. SRCL, PRCL and MICH all have whitening filters (starting at 1hz) that would need to be divided out. Kiwamu said that  LSC-POPAIR_B_RF18_I_ERR_DQ is above 600 counts when DRMI is locked.

• LVEA free-reign time moved up to 10am to allow for more commissioning time.  Check with operator/commissioners if you need to be in VEAs after 10am.
• Tuesday maintenance activities will be kept to a minimum to allow for less commissioning downtime.
• CDS at MY for 3IFO inventory
• CDS PEM mic work continues
• SUS needs to keep working on SDF
• PCal analyzing data from yesterday's work at EY

The following microphones were powered up in the corner station:

PSL, HAM2, HAM3, Vertex, Y arm spool and CER.

Each microphone power box was tested to verify both channels are working.

Filiberto C. and Sudarshan K.

Calum, Kate, Betsy

This week, we performed a series of First Contact cleaning tests on the old pilot optic ETM06 as a followup on the ring observed on the ETMy during green-arm resonance last month (alog 15928).

ETM06 has a very similar history to the installed LHO ETMs (ETM08, ETM12).  A FirstContact sheet which had the 2x 3" IAS windows was applied to ETM06 roughly 2 years ago.  After pulling the sheet this week, we observed the ring pattern, as seen on the ETMy.  Via cleaning we were able to remove a section of the ring, which implies the ring discoloration is not from etching.  Our other tests did not indicate there are any age correlations to the protective FirstContact sheets applied to optics.  Reminder - the LHO ETMs (ETMy 125ppm) have recently been measured to be low loss, so there is no current plan to further clean in-situ.

SYS/COC investigations to be continued...

model restarts logged for Thu 22/Jan/2015
2015_01_22 00:06 h1fw0
2015_01_22 00:42 h1fw0
2015_01_22 01:41 h1fw0
2015_01_22 03:05 h1fw1
2015_01_22 03:31 h1fw1
2015_01_22 04:03 h1fw1
2015_01_22 04:29 h1fw1
2015_01_22 05:37 h1fw1
2015_01_22 23:39 h1fw0

X1PLC1 10:30 1/22 2015

X1PLC2 10:31 1/22 2015

X1PLC3 10:30 1/22 2015

Y1PLC2 09:43 1/22 2015

all unexpected frame writer restarts. Recent fw period of instability ended at 5am, could be related to internal RAID diagnostics, investigation proceeding. Conlog frequently changing channels report attached.

In order for people to get some undisturbed DRMI data for glitch hunts or seismic performance evaluation, we've left the DRMI locked with the ETMs misaligned starting at 1:09 AM local time (0909 UTC).

Its been locking fine tonight with only tiny angle tweaks made after locking (but probably unneccesary). Hopefully it will relock by itself overnight. If so, the morning SEI crew ought to be able to be able to switch the seismic filter state and re-eval the control signals with only 0.1-0.2 urad tweaks to PR3, SR3, and BS.

We think that the DRMI CAL channels are out of date, but Kiwamu can probably tell us what they mean in meters units with almost no effort.

Rana, Evan

Tonight, we took some transfer functions from the ETMX/ETMY ESDs to LSC DARM IN1, when controlled by ALS DIFF. Right now we only use ETMX as our DIFF actuator (as we had previously had some trouble using ETMY), but perhaps it is time to revisit this. Using both ESDs will double our range. Additionally, by properly balancing the relative drive strengths between the two ESDs, we can make ourselves more immune to cross-coupling between the ALS-controlled DARM and CARM loops.

For the excitation we drove each L3 TEST L filter bank with 40000 ct from 10 Hz to 40 Hz.

Evidently, ETMX and ETMY have opposite signs and their gains differ by 6 dB or so (at least below 20 Hz, where the coherence is OK). Since we're aiming for a DIFF loop with a UGF of 15 Hz or so, we don't care so much what's going on above 20 Hz, so long as it's not outrageous. So we (hopefully) should be able to implement a balanced ESD drive with little trouble by engaging DIFF with both ESDs (with fiducial output matrix gains), then turning on a line in DARM, and then adjusting the output matrix gains until the line is nulled.

Evan, Alexa, Elli, Sheila, Rana,

• Evan changed the gain on the END Y TR PD to 20dB, while the X end 1 is still at 0dB (alog 16211)
• We realized that with our better recyling gain, the locking offset and gain we used last night were not sensible.  We are not using an offset in sqrt(TRX+TRY) of -1.7, which would put us at 300 pm if the recylcing gain is 30, similiar to the CARM offset that we used before.  We also estimated that the calibration into picometers should be changed from 312 to 180.  (this is the to_pm FM in TR_CARM)
• Alexa realized that the res G filter to supress 1 Hz noise in ALS DIFF was not on, turning this on reduced the RMS of ALS by about a factor of 10, helping us to stay in the linear range of TR CARM.
• We have been stable in the state PREP_TR CARM for 10 minutes or so.  We have been able to turn the gain of the ALS signal down to -11dB on the common mode board, while the TR CARM input was at a gain of 4dB.  
• We changed the low frequency boost in LSC-REFL BIAS, we are no longer engaging FM6 (a true integrator with a zero at 1 Hz).  We also changed FM5 so it is no longer a true integrator, it now has a pole at 1Hz and is turned on in PREP_TR_CARM.  We have also stopped using the lead filter in FM8, we have plenty of phase without it.  
• We measured the cross over in ALS COMM to be at 50 Hz, with 45 degrees of phase margin.

We think that we are loosing lock due to some 12-15 Hz noise in CARM which is non stationary.   We watched the spectrum of CARM locked on ALS with and without DIFF locked, and saw that the non stationary noise is only there when DIFF is locked.  We then looked back at our ALS DIFF design (alog 15025) and decided to reduce the gain by 35%. This has reduced the gain peaking, but we still have nonstationary noise in CARM.  

lock loss times: 1:44:20 UTC, 3:01:27 UTC Jan 23rd UTC lock loss durring swept sine excitation 3:55 UTC

J. Warner, A. Pele, J. Kissel

Jim has improved the isolation loop design for the HAM2, HAM3, HAM4, and HAM5 ISIs by increasing the frequency / aggression of the Level 3 isolation filters (along with tweaking the UGF and high frequency rolloff such that the aggressive boost remained stable). As such, we have a great deal more feedback gain in the 0.5 to 5 [Hz] region of all DOFs for these HAMs -- the region where the noise performance is typically loop gain limited -- and therefore the performance improvement has scaled linearly with the gain increase. See "IsoFilterComp" attachments.

We didn't have noise budget yet to prove it, but Jim had recognized that HAM6, the most recently designed chamber had much better performance, and much high boost frequency. 

Arnaud has gathered performance data comparing platform displacement before and after the change, which confirms the goodness locally. See "PerformanceComp" attachements. We didn't grab / compare the rotational degrees of freedom but these have also improved. Now that Arnaud has installed properly-matched, sensor correction, gains (see LHO aLOG 16208), we should expect a little bit better translational performance, so we'll compare again and make sure we capture rotational DOFs. Further, we plan to use calibrated DRMI cavity control signals to ensure that what we've done locally is good for the IFO.

The parameter files for these new current designs can be found here:
HAM2/Scripts/Control_Scripts/Version_3/Hori_ISO_H1_HAM2_Lv3_HR_2014_10_23.m
HAM2/Scripts/Control_Scripts/Version_3/Vert_ISO_H1_HAM2_Lv3_HR_2014_10_22.m
HAM3/Scripts/Control_Scripts/Version_3/Hori_ISO_H1_HAM3_Lv3_IMC_HP_2013_01_16.m
HAM3/Scripts/Control_Scripts/Version_3/Vert_ISO_H1_HAM3_Lv3_IMC_HP_2013_01_16.m
HAM4/Scripts/Control_Scripts/Version_3/Hori_ISO_H1_HAM4_Lv3_HR_2014_09_22.m
HAM4/Scripts/Control_Scripts/Version_3/Vert_ISO_H1_HAM4_Lv3_HR_2014_09_16.m
HAM5/Scripts/Control_Scripts/Version_3/Hori_ISO_H1_HAM5_Lv3_2014_09_25.m
HAM5/Scripts/Control_Scripts/Version_3/Vert_ISO_H1_HAM5_Lv3_2014_09_25.m

Last week, sts correction gains were measured and calculated on HAM4/5/6 to improve the CPS sensor correction. We measured them today for the remaning chambers.

For the BSC chambers, we locked the platforms to the ground by increasing the blends to 750mHz (cf alog) and turned off the sensor correction. We measured the ratio between the T240 (stage 1) and the STS (ground) signal (should be 1 with the platform moving with the ground). The same measurement was also carried out between STS and L4C for hepi, since IPS sensor correction is used for the Z DOF.

All the measurements using the corner station STS B as input to the sensor correction (ITMX, BS, ITMY) show a factor of two mismatch with the hepi and platform sensors in the X DOF only. There is certainly a calibration error with the STS B seismometer. I checked the calibration filter in the input filter banks and it looks correct (10.17 nm/s /cts). We should investigate more. The other chambers and dofs need a relatively small correction. 

The ISI gains (T240/STS for BSCs and GS13/STS for HAMs) are 

The BSC - HEPI gains (L4C/STS) are

Attached are examples of the transfer functions for ITMY 

To calculate the gains I wrote a script for the bscs in a similar fashion as Sebastien's : it is called BSC_gain_matching_calculation(IFO,Chamber,start_time,duration) located under /ligo/svncommon/SeiSVN/seismic/BSC-ISI/Common/Misc. The results above were obtained using the following parameters : 

start_time=tconvert('01/22/2015 15:35') ;
duration = 45*60 ;