Activity Log: All Times in UTC (PT)

15:00 (08:00) Take over from TJ
15:15 (08:15) Jodi – Driving to Sea Container to put things in storage
15:33 (08:33) Jodi – Finished at Sea Container
15:40 (08:40) Richard – Going into Garbing room
17:15 (10:15) LLO called – They are dropping out of Observing to make some improvements 
17:43 (10:43) Set Intent bit to Commissioning – LLO is down Keita going into CRE to work on 45Mhz
17:47 (10:47) Lockloss – Possible EQ activity NOTE: Keita did not make into CRE before lockloss
18:17 (11:17) IFO locked at NOMINAL_LOW_NOISE, 22.5W, 61Mpc
18:18 (11:18) Set the Intent bit to Observing
18:23 (11:23) Set Intent bit to Commissioning 
18:23 (11:23) Sheila – Running some measurements while LLO is recovering from Lockloss
18:36 (11:36) Karen – Swifting in the Mechanical building
18:55 (11:55) Karen - Finished in Mechanical building
19:41 (12:41) Set the Intent bit back to Observing
21:05 (14:05) Filiberto & Manny – Going to Mid-Y to recover parts
21:14 (14:14) Set Intent bit to Commissioning – Jeff K running hardware injections
22:20 (15:20) Lockloss – Unknown
22:48 (15:48) IFO locked at NOMINAL_LOW_NOISE, 22.4W, 70Mpc
22:51 (15:51) Set Intent bit to Observing
23:00 (16:00) Handoff to Travis


	

End of Shift Summary:

Title: 09/30/2015, Day Shift 15:00 – 23:00 (08:00 – 16:00) All times in UTC (PT)

Support: Sheila, Dave B.

Incoming Operator: Travis

Shift Summary: 
- 15:00 IFO locked. Intent Bit = Observing Mode. Wind is calm, no seismic activity. All appears normal.     
- 17:25 (10:25) 5.1 mag EQ in Mexico – Lost lock at 17:47 (10:47). 
-18:00 (11:00) Keita working on 45Mhz modulator during lockloss/recovery.
-18:23 (11:23) Set Intent bit to Commissioning – Jeff K & Sheila running measurements while LLO is down.

    There were two lockloss events today. The IFO recovered and relocked without much difficulty. The range has been good and environmental conditions were quiet (except for the EQ in Mexico) all day. 

 
   

J. Kissel, C. Biwer, S. Karki

We tested using PCAL as a hardware injector. We did 3 injections into the traditional H1:CAL-INJ_TRANSINET_EXC used for hardware injections in the past and 3 into H1:PCALX_SWEPT_SINE_EXC to test using PCAL for hardware injections.

All injections used the 15Hz test waveform from aLog 21838.

The first injection into H1:CAL-INJ_TRANSINET_EXC was successful. The command line was:
 awgstream H1:CAL-INJ_TRANSIENT_EXC 16384 coherenttest1from15hz_1126257408.out 1.0 -d -d >> 2015-09-30_PCALInjTest_DARMCTRLEXC.txt

We then tried an injection into H1:PCALX_SWEPT_SINE_EXC but it was unsuccessful because the injection channel list for the hinj account was restricted and did not include this channel. The command line was:
 awgstream H1:CAL-PCALX_SWEPT_SINE_EXC 16384 coherenttest1from15hz_1126257408.out 1.0 -d -d >> 2015-09-30_PCALInjTest_PCALINJ.txt

D. Barker added H1:PCALX_SWEPT_SINE_EXC to the allowed excitation channels list for the hinj account and we had a successful set of injections:
 awgstream H1:CAL-PCALX_SWEPT_SINE_EXC 16384 coherenttest1from15hz_1126257408.out 1.0 -d -d >> 2015-09-30_PCALInjTest_PCALINJ.txt
 awgstream H1:CAL-PCALX_SWEPT_SINE_EXC 16384 coherenttest1from15hz_1126257408.out 1.0 -d -d >> 2015-09-30_PCALInjTest_PCALINJ_Trial2.txt
 awgstream H1:CAL-PCALX_SWEPT_SINE_EXC 16384 coherenttest1from15hz_1126257408.out 1.0 -d -d >> 2015-09-30_PCALInjTest_PCALINJ_Trial3.txt
 awgstream H1:CAL-INJ_TRANSIENT_EXC 16384 coherenttest1from15hz_1126257408.out 1.0 -d -d >> 2015-09-30_PCALInjTest_DARMCTRLEXC_Trial2.txt

We then tried another injection but NDS happened to fail as we tried the injection and the injection was unsuccessful:
 awgstream H1:CAL-INJ_TRANSIENT_EXC 16384 coherenttest1from15hz_1126257408.out 1.0 -d -d >> 2015-09-30_PCALInjTest_DARMCTRLEXC_Trial3.txt

The problem was quickly fixed and we set up to retry the injection. It was successful:
 awgstream H1:CAL-INJ_TRANSIENT_EXC 16384 coherenttest1from15hz_1126257408.out 1.0 -d -d >> 2015-09-30_PCALInjTest_DARMCTRLEXC_Trial4.txt

The logs are attached.

The end times of the injections should be:
DARM 1             1127683334.985681295
PCAL 1              1127683905.985681295
PCAL 2              1127684170.985681295
PCAL 3              1127684464.985681295
DARM 2             1127684765.985681295
DARM 3             1127685142.985681295

As we were doing the injections we made omega scans, they can be found in aLog 22123.

C. Biwer, J. Kissel

Taking advantange of single IFO time to run PCAL vs DARM hardware injections. More details later.

C. Biwer, J. Kissel

Taking advantange of single IFO time to run PCAL vs DARM hardware injections. More details later.

Tuesday 29 September 2015 John and Gately replaced the vibration isolators on end instrument air compressors. So here I follow up the correlation between the glitches and the EX_SEIS_VEA_FLOOR_[X,Y,Z]_DQ commented by Joshua (21470). I have analyzed data from the 09/29 10.00 UTC before the repair and the glitches are totally visible. The data after the repair 09/30 10.00 UTC shows no trace of the glitches. I attach two images to show these.

Now that we've cleaned up all of our systematics from the DARM model and released the O1 version (see LHO aLOG 22056, I've updated the diagram that explains how the actuation path clock cycle delay is derived, and also shows that the current value of 7 [clock cycles] or 427.3 [us] that was recently installed at both sites (LHO aLOG 21788) still does a fine job at approximating the total delay between the inverse sensing and actuation chains.

[Aidan, Alastair]

We ran a calculation of the coupling of intensity noise to displacement noise for the CO2X laser at LHO. The details are as follows:

"The absolute coupling is very low right now due to the small amount of power being used to heat the test masses. The transfer function has not been directly measured but we have an estimate for it in the following document:

One lock loss today due to an earthquake in Mexico. LLO also lost lock around the same time. 

The IFO recovered and relocked with relative ease. We have been locked at NOMINAL_LOW_NOISE for the past 2.25 hours. The Intent Bit was set to commissioning from 18:23 to 19:41 while Sheila was running some tests. The Intent Bit was set back to Observing at 19:41 (12:41)

Note:

• AOM diffrated power is leaning towards the 'high' side
• This report is following a lockloss due to an earthquake

In the attached, left is the trend of 45MHz signals after the driver swap in the PSL room. Signals named MOD_RF45 are from the PSL room, MOD_9MHz are actually from the old unit now installed in CER (and it's not 9MHz, it receives 45MHz signal from the 45MHz distribution amp).

Anyway, the new driver remained very glitchy for 6 or 7 hours but we don't see any correlation with the CER unit, then it became quiet for the rest of the night except three easily visible glitches. The largest one was about 0.06 counts pk-pk in the control signal.

But the old driver had good and bad period. For example the day before (middle panel) it was mostly quiet, but three days ago (right panel) it was nasty, and the largest glitch there was about 0.14 counts pk-pk.

Two things we learned so far are:

• Glitches in the PSL room unit are NOT due to the driver/stabilization circuit, as the one in CER ("9MHz") is the old one pulled from PSL yesterday and it's much less glitchy.
• Glitches are NOT from the distribution amplifier itself or upstream as the two units don't glitch at the same time.

When DTT gets data from NDS2, it apparently gets the wrong sample rate if the sample rate has changed. The plot shows the result. Notice that the 60 Hz magnetic peak appears at 30 Hz in the NDS2 data displayed with DTT. This is because the sample rate was changed from 4 to 8k last February.  Keita pointed out discrepancies between his periscope data and Peter F's. The plot shows that the periscope signal, whose rate was also changed, has the same problem, which may explain the discrepancy if one person was looking at NDS and the other at NDS2. The plot shows data from the CIT NDS2. Anamaria tried this comparison for the LLO data and the LLO NDS2 and found the same type of problem. But the LHO NDS2 just crashes with a Test timed-out message.

Robert, Anamaria, Dave, Jonathan

I think it's possible that we're closer to the Newtonian gravitational noise limit than I had thought.  This is on the list of "things we knew were coming, but are perhaps here sooner than I thought they would be". 

The punch line is that we may be limited by Newtonian noise between 16-20 Hz.  Not a wide band, but reasonably consistent with the expectations from papers such as P1200017.

In the attached plot, the blue trace is the calibrated DARM spectrum (CAL-DELTAL_EXTERNAL_DQ) that we show on the wall, taken yesterday.  The green trace is my estimate of the Newtonian noise. 

For the Newtonian noise, I have taken the Z-axis STS-2 seismometer data from the sensors on the ground near each test mass.  (There is one seismometer at each end station, and one in the vertex near the ITMs - I use the same seismometer data for each ITM). The seismometers are in velocity units (I believe Jim said it's nm/s), so I pwelch to get velocity/rtHz, then apply the calibration zpk([],0, 1.6e-10) to get to meters/rtHz.  I then translate to acceleration due to Newtonian noise using eq 1 from T1100237.  Finaly, I add the 4 acceleration contributions (one from each test mass) incoherently and get to displacement by dividing the spectrum by (2*pi*f)^2. 

The Newtonian noise is touching the DARM spectrum between about 16 - 20 Hz. We're within about an order of magnitude in the band 10 - 30 Hz.  Evan will shortly re-run his noise budget code using this "measured" Newtonian noise to see if it helps explain some of the discrepancy between the measured and expected DARM spectra (this spectra is higher than the GWINC curve that is currently used in the noise budget). 

Notably, this estimate of seismically-induced Newtonian noise is somewhat larger than what we've quoted in P1200017 and T1100237.  If I use only the ETMY spectrum as an estimate for all 4 test masses, I get an answer more consistent with our past estimates.  However, using the actual seismic signals from each test mass, I'm getting this slightly higher estimate. 

The script to generate this plot is attached, as is the exported-from-DTT text file of the calibrated DARM spectrum.