Title:  10/06/2016, Day Shift 15:00 – 23:00 (08:00 - 16:00) All times in UTC (PT)
State of H1: IFO lost lock due to PI ring up. IFO was coming back up when I came in. Was able to damp PIs M2 and M10. IFO relocked at NOMINAL_LOW_NOISE with no problems	   
Outgoing Operator: N/A
 
Activity Log: All Times in UTC (PT)

14:20 (07:30) Chris & Apollo – Going down Y-Arm to work on beam tube sealing near CS
14:30 (07:30) Damped PI modes M2 & M10 – IFO relocked at NOMINAL_LOW_NOISE	
14:50 (07:50) Robert – In LEA doing injections
15:10 (08:10) Peter – Going into PSL to adjust power & install new PD (WP #6219)
15:10 (08:10) Christina – Forklift crate from LSB to Mechanical building
15:12 (08:12) Richard – In MSR to replace batteries (WP #6218)
15:15 (08:15) Karen – Cleaning in Optics Lab
16:00 (09:00) Kiwamu – Going into PSL for PD install (WP #6219)
16:09 (09:09) Karen Out of Optics Lab
16:20 (09:20) Peter & Kiwamu – Out of PSL
17:32 (10:32) Robert – Running injection
21:45 (14:45) Dave – Adding new DBB signals to frames & DAQ restart (WP #6220)


Shift Details: 10/06/2016, Day Shift 15:00 – 23:00 (08:00 –16:00) All times in UTC (PT)
Support: Cheryl,               
Incoming Operator: Travis

Shift Summary:  Broke lock around 14:00 (07:00) due to PI ring up. At around 14:30, damped PI Mode #2 by changing phase from 30 to 80 and PI Mode #10 by changing phase from 30 to 80. Modes responded quickly and we relocked at NOMINAL_LOW_NOISE with no problems. 
PI Modes 2 & 10 rang up again – damped mode 2 buy changing phase from 80 to 30. Damped Mode 10 by changing phase from 80 to 60.
Most of shift spent in commissioning and relocking. 

Following up on entry 30273, I computed the coherence and transfer function between ISS_PDA_REL_OUT (which should be calibrated in RIN units) and CAL-DELTAL_EXTERNAL (including the proper calibration). Coherence is good enough to estimate a transfer function over all the frequencies above 10 Hz. I'm not injecting any additional noise, just using the signals as they are, so the fact that we have coherence doesn't necessarily mean that we really have a coupling of intensity noise to DARM.

However, the transfer function has a very interesting shape (see figure). It's behaving like 1/f^3 up to ~80 Hz, and above that frequency it increases like f. The region below 80 Hz might very well be consistent with radiation pressure coupling of intensaity noise. We'll have to run some numbers to be sure that this makes sense. I have no clear explanation of the increase above 80 Hz.

Addition:

A quick and dirty estimate of the expected coupling of RIN at the ISS PDs to DARM due to radiation pressure

x = 2 deltaP / c / (m * (2*pi*fr)^2) / (fr / fr_pole_doublecav) = 2 P_arm / c / (m * (2*pi*fr)^2) / (fr / fr_pole_doublecav)  * RIN

At 30 Hz the coupling should be about 2e-11 (maybe off by a factor of 2 or so due to the two arms, etc..). This is many orders of magnitude LARGER than what measured in the TF discussed above. So it is unlikely that PDA/PDB see real intensity noise that goes into the IFO.

I ran a BruCo scan for the last night lock, using ten minutes of data when the range was at ~65 MPc. Results are available here:

https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_1159774937/

Summary

There is a lot of coherence a bit everywhere:

• at low frequency (<100 Hz) the auxiliary longitudinal d.o.f.s win: MICH, SRCL, PRCL, see figures 1,2 and 3
• below 50 Hz the most significant angular control signal is ASC-AS_B_RF45_Q_YAW (fig. 4)

The "jitter noise" above 100 Hz shows a lot of coherence with many signals, of different origins. Most of the IMC WFS signals are coherent, for example: IMC-WFS_A/B_DC_PIT/YAW_OUT (fig. 5 and 6).

The most interesting coherence is however with the intensity stabilization: PSL-ISS_PDA_REL_OUT and PSL-ISS_PDB_REL_OUT shows quite large coherence, as well as the ISS control signal: PSL-ISS_AOM_DRIVER_MON_OUT. It seems that PDA and PDB (first loop ISS) are completely dominated by what the ISS second loop is doing (as shown by the control signal). The coherence with DARM in the 100-1000 Hz region is very close to one. See fig. 7 and 8.

Note that in the same 100-1000 Hz region, the coherence with PSL lab accelerometers is also significant, but mostly on the peaks (fig. 9)

En passant, a narrow feature at 56.75 Hz and 113.50 Hz are coherent with EX magnetometers (PEM-EX_MAG_EBAY_SEIRACK_X/Y PEM-EX_MAG_VEA_FLOOR_Y/Z)

Multicoherence

I selected the channels with the largest coherence from the BruCo report, and run a multicoherence code.

chnames = {'H1:LSC-MICH_OUT_DQ', 'H1:LSC-SRCL_OUT_DQ', 'H1:LSC-PRCL_OUT_DQ', ...
            'H1:ASC-AS_B_RF45_Q_YAW_OUT_DQ', 'H1:ASC-OMC_B_YAW_OUT_DQ', 'H1:ASC-OMC_B_PIT_OUT_DQ', ...
            'H1:LSC-REFL_A_RF45_I_ERR_DQ', 'H1:LSC-REFL_A_RF9_Q_ERR_DQ', 'H1:IMC-WFS_A_DC_PIT_OUT_DQ', ...
            'H1:IMC-WFS_B_DC_PIT_OUT_DQ', 'H1:IMC-WFS_A_I_YAW_OUT_DQ', 'H1:IMC-WFS_A_Q_YAW_OUT_DQ', ...
            'H1:PSL-ISS_AOM_DRIVER_MON_OUT_DQ', 'H1:PSL-ISS_PDA_REL_OUT_DQ', 'H1:PSL-ISS_PDB_REL_OUT_DQ', ...
            'H1:PSL-ISS_SECONDLOOP_RIN_INNER_OUT_DQ', 'H1:PSL-ISS_SECONDLOOP_RIN_OUTER_OUT_DQ', ...
            'H1:PSL-PMC_HV_MON_OUT_DQ', 'H1:IMC-IM4_TRANS_SUM_OUT_DQ', ...
            'H1:PEM-CS_ACC_PSL_TABLE1_X_DQ', 'H1:PEM-CS_ACC_PSL_TABLE1_Y_DQ', 'H1:PEM-CS_ACC_PSL_TABLE1_Z_DQ', ...
            'H1:PEM-CS_ACC_PSL_PERISCOPE_X_DQ'};

The code take into account the cross-coherences between channels and produce the total coherence and an estimate of the noise projection, base on that coherence. The last figure (10) shows this coherence and the projection into the DCPD signal. A lot of noise can be explained by the coherences.

So, apparently Peter went into the PSL this morning and adjusted the HWP to give us more power incident on the rotation stage.  However, this was not communicated to commissioners / people in the control room, so the ISC_LOCK guardian was still requesting 60W.  With the hardware change, this was actually giving us ~60W into the vacuum.  Something in the ASC didn't like this, and we lost 2 locks after ~1 hour each, with something drifting away. 

EDIT:  I guess some commissioners did know that we were getting 60W and decided to try running with it, we just didn't think it would have such a deleterious effect on the ASC.

The only oplev which is furthest off (approaching -10urad) is the HAM2 oplev (pit & yaw).  This closes out FAMIS#4696.

J. Kissel, S. Karki

As we've done in O1, we're creating a high-frequency ( > 1 kHz ) excitation via PCALX whose frequency is changed over long-duration in order to map out the interferometer's sensing function out to as high as is needed for burst and binary neutron star coalescence searches. For quite some time now (since July! see LHO aLOG 28301), this line has been gathering data at 3501.3 [Hz]. We haven't moved it because the IFO's duty cycle has been low, the power level has been inconsistent, and our person power has been limited.

Today is the day!

I've resumed moving this line, following the schedule posted by Sudarshan in LLO aLOG 28070, which I repeat here for convenience:

Frequency    Planned Amplitude        Planned Duration      Actual Amplitude    Start Time                 Stop Time                    Achieved Duration
(Hz)         (ct)                     (hh:mm)                   (ct)               (UTC)                    (UTC)                         (hh:mm)
---------------------------------------------------------------------------------------------------------------------------------------------------------
1001.3       35k                      02:00      
1501.3       35k                      02:00     
2001.3       35k                      02:00     
2501.3       35k                      05:00      
3001.3       35k                      05:00                   39322.0           Oct 06 2016 18:39:26 UTC
3501.3       35k                      05:00                   39322.0           Jul 06 2016 18:56:13 UTC    Oct 06 2016 18:39:26 UTC      months
4001.3       40k                      10:00
4301.3       40k                      10:00       
4501.3       40k                      10:00
4801.3       40k                      10:00  
5001.3       40k                      10:00

Several things to note: 
- The line frequency was changed in the middle of the lock stretch.
- This lock stretch has been with the PSL power at 58.7W (we hope to run ER10 / O2 at 50 W).
- Alignment of SRC optics is being slowly changed by commissioners
- Robert has also been playing with Intensity Noise coupling, which is currently limiting the sensitivity at these high frequencies, so the SNR of the line may be varying quite wildly.

   Posted are the plots for the BSC and HAM ISI CPS noise spectra. All plots are near or below the reference and there are no particular CPS noted. Closed FAMIS task #6866  

TCS-X: No additional water required, water level 29.0, 3.7 gpm, 20.1 deg. C.

TCS-Y: Found water level at 5.8, added 300 mL water, raised water level to 9.8, 4.0 gpm, 21.0 deg. C.

Not that it is a concern but attached is a plot of the Long Range Actuator (LRA) position versus the
laser room temperature.  I only note it because the 32 micron travel is perhaps the longest I've seen
it move, and represents 64% of the available travel before a PZT reset.

    The data dropout corresponds to the DAQ restart at 23:02 UTC yesterday.

I tried a few things to look around for a useful signal for SRM ASC at 50W, and had no luck. 

I am pretty convinced that there's no signal that's useful in REFL45 for the SRM.  I couldn't get rid of the ~0.16 Hz oscillation that we see in the PRC1 and PRC2 control signals, which I tried in an effort to see something better in REFL45.  (I tried adding res-gains in both PRC1 Pit and PRC2 pit, to no avail.  Out of loop motion as measured by POPB didn't change.)  I eventually tried "cheating" by lowpassing the REFL45A pitch and yaw I signals (these are not in-loop for anything), but there's really nothing at all there for the SRM.  I also tried moving SR3 (after disabling the cage servo), but that also didn't really have a good signal anywhere but AS36B.  Both SRM and SR3 have an okay signal in AS36B, but I was hoping to find something that wouldn't leave us back in the "sensing matrix of the day" regime. 

Interestingly, the noise at high frequencies seems to get better when POPAIR90 is higher and rattier.  I'm not sure right now why a misaligned SRC would help suppress frequency noise. 

I tried Nutsinee's CSOFT offsets from the other night (alog 30085), and while they do seem to improve the sensitivity in the bottom of the bucket, they noticeably reduce the power recycling gain.  I tried a few other offsets, but I think 0s everywhere for the SOFT loops is about the best in terms of power buildup.  I was running a2l at each offset, and the calibration lines at 330 and 1100 Hz were roughly constant, so I don't think I was fooling myself too much.  So, why do we get better sensitivity in the bucket with lower recycling gain (28 rather than 30)?  I see the buildups go down in the arm transmissions as well as POPDC, so it really is a reduction in the recycling gain. 

Note to self for the morning:  Were good / bad range times really correlated with times when the AS90 dark offsets jumped?  It vaguely seemed that way, but I need to check.  The AS90 signal would occassionally pop up and be visible on the front tv striptool, even though it should be too low for that with the beam diverters closed.  It was sudden jumps, not obviously related to alignment changes, so I think it was dark offset changes.  If that's true, do we need to finally figure out why the electronics at the HAM6 rack are so finicky?  No one was out in the LVEA, so I'm not sure why the offsets were changing.

TITLE: 10/05 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Ready to go to Observing when Jenne is done.
INCOMING OPERATOR: Travis
SHIFT SUMMARY: Locking has been going well. Unlocking has also been going well. No issues to report.
LOG:

23:02 DAQ restart

23:14 Nutsinee to LVEA Hartmann work

23:30 Initial alignment

0:02 Nutsinee out

5:50 Nutsinee filling TCSY chiller

6:00 End of shift due to Guardian training early shift start (22:00)

NOTE to Commissioners: In order to get Guardian to let us go to Observing we had to (and will have to fix later):

• Put DIAG_SDF into the ignore list.
• TCS_CO2_PWR nominal state changed
• Changed the run state of 'PREHEATING' to simply return 'True'.  Commented out any checks.
   

DTT is once again not ramping down excitations.  The exciting new "feature" here is that it's not just upon an Abort.  Even when the measurement completes fully, it still just immediately stops the excitation.

This has caused 1 lockloss so far tonight, and 2 scary glitches that could have been locklosses. 

I attach my DTT settings - Noise (Gauss), and I do have a ramp up/down times defined. 

-----

Looking at it again (still running measurements, just hoping for the best when they complete), it looks like it waits and leaves the excitation on for the number of seconds set in the RampDown box, and then cuts it off.  So, the excitation doesn't get suddenly cut off as soon as I click Abort, it gets suddenly cut off 3 seconds after I click Abort.

• The sleds were swapped back and re-swapped to do the same test as alog29956 (I forgot to swap the launchers then). The result was we had no reflection back from ITMY and ITMX had both 790 and 840 nm reflections. So we didn't learn much from this test. The sleds are now swapped back (790nm on X, 840nm on Y)
• The code has been restarted. No new reference has been taken yet. Waiting for a cool IFO.
• The 840nm sled S/N 07.14.264 is dead. I replaced it with 07.14.265.
• The current sled power calibration is again slightly off from alog25806. I don't see a more recent alog of it being re-calibrated so I'm putting the values back to where it was. I tried to measure the power but I had a hard time zeroing my meter so I don't trust my measurement so much (I measured HWSX sled to be outputting 3mW, HWSY sled 5mW). I accepted the changes in the SDF.

Related: alog 30221

In addition to what Daniel has posted, I measured the coherence and DBB QPDs again, this time in nominal low noise.

Probably due to lower IFO noise, the coherence is larger and broader, extending down to 70Hz or so.

The differences between today and yesterday are:

• Used pre-alignment servo to center the beam on QPDs, and then held the output of the PZT filters. So this is still totally open loop but the centering is much better.
• DBB PMC is kept very close to anti-resonance by adding offset to DBB PMC length PZT manually. During the measurement, transmission PD output was lower than 1.1mV. Compare this to about 8 or 9V when in resonance.
• IFO was in nominal low noise.
• The plot shows DCPD_SUM scaled arbitrarily by 3E6 instead of DELTAL_EXTERNAL.

I kind of think I saved the new alignment slider values after changing the alignment slider gains on Sept. 30th, but found them at the old values in SDF.  I accepted the new values.  Screenshot attached.