Support: Jeff K., Jenne, Kiwamu, Peter K., Sheila

At the beginning off the shift I changed the power_sepoint in lsc_params.py from 20 to 40 and loaded it.

After a lock loss from 40 W we started having FSS and ISS issues similar to what TJ (alog 28034) and Sheila (alog 28045) had reported last night. Kiwamu was able to find and address the problem (alog 28058).

A couple of times the guardian did not appear to recognize a lock loss and thus did not take the IFO to down. I had to do so manually.

There were occasional notifications that the POP X PZT had railed and that the IMC WFS were not centered. There were also notifications that the TCSX and TCSY CO2 power was off by more that 0.05 W.

Stefan fixed a bug in the DRMI down state (alog 28053).

I ended the shift having trouble locking DRMI and handed it over to TJ to run an initial alignment.

14:58 UTC Peter to LVEA PSL racks to reset noise eater
16:08 UTC Bubba and Nicole to mid X
16:57 UTC Karen and Christina to mid X and mid Y to clean
17:02 UTC Ed to CER to reset DBB AA/AI chassis (alog 28049)
17:52 UTC Karen leaving mid Y
18:07 UTC Christina leaving mid X
18:19 UTC Ryan patching alog
21:44 UTC Kyle refilling CP3 (alog 28062)
22:03 UTC Kyle back

biggest = prm pitch changing by 2.5urad

close second = im4 pitch changing by 1,15urad

plot and chart of top 16 optics/DOFs attached

1450 - 1505 hrs. local -> To and from Y-mid 

Opened exhaust check-valve bypass, opened LLCV bypass valve 1/2 turn -> LN2 at exhaust in 50 seconds -> Restored valves to as found state.  

Next CP3 over-fill to be Friday, July 1st.  

Kiwamu, Stefan

We were trying to nail down what is responsible for the Power Recycling Gain change during power-up, so we went through the whole sequence slowly, and gave the system time to settle in each state:

All times UTC of 20160629:

- 18:54:37 / Green dot: Power-up starts from 2Watt to 10Watt
- 19:00:32 / Red dot: Power-up restarts from 10Watt to 40Watt
- 19:06:10 / Black dot: : Power-up to 40W finishes, but additional SOFT offsets remain left off.
- 19:10:15 / Blue dot: Soft offsets in yaw start ramping on over 2 minutes
- 19:12:17: Soft offsets ramp in yaw is done
- 19:15:17: Soft offsets in pit start ramping on over 3 minutes
- 19:18:19: Soft offsets ramp in yaw is done
- 19:21:20: End of undisturbed period - guardian continued
 

In particular, we now there is a significan power recycling gain improvement with a soft yaw adjustment of the x-arm. Additionally, the beam splitter cannot affect the relative alignment of x-arm and power recycling cavity. SO attached are only yaw signals from x-arm and power recycling cavity.

Conclusions:

- During the very first step in power up (green dot) there is a momentary shift in PRM yaw and IM4 yaw, but it does not continue during the additional power increase.
- During the main power increase (between red dot and black dot). There is a consiostent signature in the ETMX control, oplev and IR camera signal, sggesting that we are slightly moving the x-arm with the ASC system. THe ITMX doesn't see much of this in control signal and oplev signal (its camera is broken and not plotted). However no significant motion is visible in any of the power recycling cavity mirrors (this includes PR2, which is not plotted).
- Once we start moving the soft loops with soft offsets, ETMX, ITMX, PR3 and BS clearly respond. Interestingly, the ETMX moves to the same direction as during the power increase.

• I have defined an earthquake state in the SEI_CONF guardian. This state currently just turns off all sensor correction to the the HAM ISIs (X,Y&Z) BSC-ISIs (X&Y), BSC HEPIs (Z) and HAM1 HEPI (X,Y&Z). Following the IFO surviving a small earthquake last night, I could believe that it might work as intended, at least during an otherwise quiet ground environment (low wind, low microseism).
• The dream would be to add automation or operator notifications. Terramon being down makes this harder. When are we getting an epics variable? Otherwise, TJ and I have talked about an environment guardian.
• Chris Buchanan has a study of O1 earthquake statistics (G1600348), it would be nice to get more detail about what IFO signals were impacted by earthquakes during O1, so we know what signals to look at. IMC-F and LSC-X/Y_TIDAL_MON seem like good starting points. Chris's DCC doc includes a link to an earthquake wiki with a lot of information.

Last night at about 23:30 UTC last night, we had an earthquake arrive at LHO. I don't know where it was or how big, because Terramon has been down for a while. The peak BLRMS displacement seen by the ITMY STS in the .03-.1hz region was .28 microns. The first thing I noticed was the IMC F and LSC Y TIDAL on the Tidal StripTool were showing large ~20 second oscillations. When Sheila switched to  the "Earthquake" SEI_CONF state, these oscilations went away, even though the earthquake band ground motion continued going up. My first plot shows the SEI_CONF state ( 40 is the windy state (SC on everywhere), 17 is the earthquake state) ITMY Z .03-.1hz BLRMS displacement in nm, IMC-F and LSC-Y_TIDAL_MON. You can see that at about the time the ground motion BLRMS gets to about 100nm, the IMC and LSC TIdal starts ringing up. As soon as the sensor correction is turned off, the IMC and Tidal settle down. This lock lasted in this configuration past the earthquake, until the commissioners tried to move to a higher guardian state.

The next two images are two times later in the evening, one when the SEI_CONF was still in the earthquake mode (6/29/2016 1:10 UTC), the other after the later lockloss when the commissioners had changed back to the "Windy" SEI_CONF state (6/29/2016 2:13 UTC). IMC and Tidal don't seem to be bothered by either state. The newt four images are various spectra comparing IFO control signals at these two times. Unfortunately it looks like there was maybe another small earthquake and higher winds when the SEI_CONF was still in "earthquake". All "REF" traces are with the earthquake configuration, the live traces are with the windy configuration. I think these spectra show that for now we can be in either state, but some of the suspension length signals show lower drives with the "windy" config. Additionally, the earthquake config will probably not be okay with higher microseism, we have been sitting at about 10th percentile levels for a while now. The last plot just shows the effect of turning of the (BRS subtracted, STS based) sensor correction on the ETMY ST1 T240s. The Y blend is the same for both blue and pink traces. The subtraction at the microseism doesn't look good right now, but I think that is because of the low microseism.

DBB:

.001 files= Lo Power

,002 files = Hi Power

As expected beam pointing and mode matching in the Hi Power path remain to be addressed. 

ISS_RPN:

It looks like AOM diffraction noise is high consistent with the higher-than-usual measured diffracted power.

PDB is "in-loop" and noise is ≈ 1 oreder of magnitude higher than reference.

Pointing noise in X-axis seems to be elevated in the regions between 12Hz & 80Hz. Also, there is some Y-Axis noise between 100Hz & 850Hz.

Lisa asked me to run a BruCo scan on data from this elog entry: 27990 (June 28, 6:00 - 6:10 UTC)

The report is available at the following address:

https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_1151128817/

Instead of CAl_DELTAL I used directly the OMC_DCPD_SUM signal. The reason is that the usual calibration of CAL_DELTAL does not seem to be correct anymore.

In summary:

• All noise below ~70 Hz is dominated by alignment signals (CHARD, SRC, PRC2, PRC1, INP2). CHARD seems to be the one with largest coherence. There's also large coherence with ASC-OMC_A/B_SUM. I'm not sure if this is ok (they may be the same DCPD signals) or if those signals are sampling the beam before the OMC. In the latter case, it might indicate that the coupling of angular noise goes through some high order modes or clipping.
• However, coherence is also large with MICH / PRCL / SRCL, so it's hard to say what's going on. Are the auxiliary channels feedforward paths on?
• At higher frequencies I couldn't find much going on, except maybe a larger than usual coupling with IMC jitter, see last plot.

For future reference, to run BruCo you can follow this procedure

1. log in into one of LDAS machines, for example ldas-pcdev1.ligo-wa.caltech.edu
2. download the bruco code from the git repository https://github.com/gabrielevajente/bruco
3. read the first lines of the bruco.py script for instructions. To produce the report above I used the following command:
   ./bruco.py --ifo=H1 --channel=OMC-DCPD_SUM_OUT_DQ --gpsb=1151128817 --length=600 --outfs=4096 --naver=300 --dir=~/bruco_1151128817 --top=100 --webtop=20 --xlim=1:1000 --ylim=1e-10:1

So, I've taken the NPRO "RRO" (which is LASER speak for Resonant Relaxation Oscillation - what is that?? right?) status indicator from the PSL_LASER.adl screen and copied it to the FSS_LASER.adl screen and aptly enhanced the label to include the term "NOISE EATER" which is a term that we would more likely be familiar with. It's located in some prime real estate just South of the "Oscillation Threshold [v]" setting.  I did this at the advice of Peter King in response to the issues that have recently arisen regarding the FSS trying to re-lock after being "kicked" by a lock loss. In the usual tradition, GREEN=Good and RED=Bad. 

Jeff had a lock loss during the coil switching. This state temporarily changes the suspension output matrix. The lockloss however prevented setting the matrix back, and no DOWN state took care of that.

I added corresponding code into the DRMI down state:

        # put back in regular matrix
        coilburtpath = '/opt/rtcds/userapps/release/isc/h1/scripts/sus/'
        stage='M3'
        for optic in ['PRM','PR2','SRM','SR2']:
            ezca.burtwb(coilburtpath+ optic.lower() + '_' + stage.lower() +'_out_normal.snap')
        optic='BS'
        stage='M2'
        ezca.burtwb(coilburtpath+ optic.lower() + '_' + stage.lower() +'_out_normal.snap')
        time.sleep(1) # for burt to work
        stage='M3'
        for optic in ['PRM','PR2','SRM','SR2']:
            ezca['SUS-' + optic + '_' + stage + '_EUL2OSEM_LOAD_MATRIX'] = 1
        optic='BS'
        stage='M2'
        ezca['SUS-' + optic + '_' + stage + '_EUL2OSEM_LOAD_MATRIX'] = 1
 

In looking at HAM2 optics, I noticed that all three IMC optics, MC1, MC2, and MC3 have alignment changes from before to after Mantenance yesterday.

Sliders did change, however I can see where the old safe.snap alignment offsets were loaded, and then corrected, for MC1 and MC3.  MC2 is odd because I don't see where the safe.snap alignments was loaded since it's alignment offsets are not seen on MC2 in the same time frame.  I started my plot at 6/28 at 15:00UTC which is 8AM local, when Maintenance starts.

IM4 Trans pitch and yaw also changed by 0.02 (+ for pitch, - for yaw).

While trying to initiate "Manual" mode to begin DBB scans, the DBB Interlock tripped. The resetting of one or both of the AA/AI chassis seems to be the "fix" for this. See: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=27404

BSC ISI model updates successful
charge measurements rescheduled for Thursday morning
new wire successfully run for PT100
CP5 still being worked on
property audit ongoing

Marie, Sheila, Kiwamu, Lisa, Stefan

We tried a few things to improve the recycling gain tonight. We  believe that the problem is with something in our PRC.  We can see that the green power transmitted through the X arm stays stable as we power up, we think this means the optics are stable.  When we move the soft offsets to improve the recycling gain we change the X arm alignment to follow something in the vertex.

• We started with dithering IM1+IM3.  The IM1 dither was meant to test is we were clipping into the Faraday, we don't think that is happeneing because we could clearly see our dither in IM4 trans PIT and Yaw, but not in the sum. 
• We tried moving IM3 and PR2 offsets.  We saw taht IM4 trans pit moves as we power up, so we started by trying to correct this by moving IM3. We were repeatably able to improve the reycyling gain from 28 to 29 by moving IM3 by 3000 in pitch counts (we think this is calibrated in urad! Our inital starting point was 58495 on the IM3 pit slider, our best recycling gain was at 55515 urad).  This seems like too big of a move to be the real drift that we are trying to correct, and is much larger than the move needed to correct the position on IM4 trans. 
• We tried moving loop offsets in PRC2 (POPX-> PR3 loop) In pit we went +- 400 counts without seeing any real change, in yaw we saw a repeatable imprvement with a offset of +400 counts. 
• We switched off the loop, moved optics, and broke the lock. 

As TJ noted, since the computer problems earlier we are having trouble relocking the PSL after locklosses, with noise eater, PMC and FSS and ISS problems.  It seems like trying to lock the FSS causes the noise eater to oscillate again after it has been reset. 

Manually set CP5 LLCV to 10% open to lower LN2 level, then adjusted % full set point to 98% and switched to PID mode to maintain overnight.

Evan G., Darkhan T., Travis S.

Both end station PCals were calibrated today during the maintenance period.  Stay tuned for results.

(Richard M, Fil C, Ed M, Daniel S)

ECR E1600192.

Split Whitening Chassis S/N S1101627:

• On the interface chassis remove R7, R8, R9 and R10, R17 and R18 (disconnects in-vac cables and Z-switch).
• On the interface chassis jumper 220 pF capacitors on J3 between pins 1-3, 9-11, 2-4 and 10-12 (adds one pole of high pass at 7.2 kHz).
• On the 2nd whitening board remove C37, C38 and C39 (removes both poles of low pass).

AA Chassis S/N S1102788 & S1202201:

• On channels 15 and 16 remove C1, C6 and C9 (two poles of 10 kHz low pass).
• On channels 15 and 16 remove C7 (one pole of 10 kHz low pass).
• The twin-T notch was left in. It is fairly wide and attenuates ~17 dB at 50 kHz.

The attached plots show the transfer functions of

1. whitening chassis: OMC DCPD_A: same as before
2. whitening chassis: OMC PI DCPD_A: modified
3. whitening chassis: OMC DCPD_B: same as before
4. whitening chassis: OMC PI DCPD_B: modified
5. AA chassis: channel 15
6. AA chassis: channel 16

The OMC DCPDs have proven to be useful for monitoring the test mass acoustic modes around 15 kHz, but there is a lot of low-pass filtering in the readout chain that render them less useful for monitoring higher frequency acoustic modes. This is now being changed with modifications to the electronics that will provide separate, faster channels for PI monitoring:

• In-vacuum pre-amp: this has 2 poles at 16 kHz (these will remain, since in HAM6)
• Whitening board: 1 pole at 14 kHz; 1 pole at 18 kHz. These will be eliminated in the new chain.
• Anti-alias filter: 3rd order Butterworth low-pass at 10 kHz. These will be eliminated in the new chain.

The attached plot shows the magnitude response of the low-pass filtering in the previous case, and with the poles removed from the whitening and AA channels. It is no wonder that no PI modes have been seen above the 15-16 kHz grouping, as there is 40 dB of relative attenuation already at 25 kHz.

I also attach a 1kHz - 10 MHz transfer function of the in-vacuum DCPD readout that Koji measured at Caltech:

https://nodus.ligo.caltech.edu:8081/OMC_Lab/235