TITLE: 07/14 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 133Mpc
SHIFT SUMMARY: H1 has been locked for 21 hours and observing for 8 hours. Very quiet evening with one earthquake passing through.

• Finished commissioning at shift start; observing @ 23:02
• Incoming 5.3 earthquake from Japan @ 02:20; rode through without switching to EQ mode

Handing off to Corey for the night.

LOG:

No log for this shift.

Dan Brown, Cao, Kevin K., Elenna

I made a plot comparing the high frequency DARM spectrum around 10 kHz comparing our current 60W configuration to the configuration we had the last time we were at 60W, specifically April 6. These plots were both made well into each lock, so the thermal transients had settled. I believe they are an apples-to-apples comparison of the high frequency region for these two locks and IFO configurations. Three features stand out as different between the two spectra: the 2nd order HOM peaks are not in the same location, they are not the same height, and the overall DARM spectrum is lower in the blue trace (April), than the red trace (now). This indicates that the arm modes are not as well matched now as they were in April, and the frequency noise noise now is higher by a factor of 1.7 than it was in April.

If nothing else had changed in the IFO, we should have been able to successfully revert to the blue trace by powering down and reverting all other settings.

I think the reason we haven't been able to revert to the previous 60W state is related to the mysterious changes that occurred on and after May 19 when the HVAC caused many issues. Whatever changed in May caused us to ring up a PI, increased the jitter noise, and changed our mode matching. My hypothesis is that the alignment shifted in some way. Unfortunately none of the suspension, oplev or ISC signals indicate an alignment shift.

I asked Cao to take a look at the ITMX hartmann wavefront sensor. Cao made the following two plots: one showing the center of the beam position in x (yaw) and y (pitch), and the other showing a heat map of ITMX. The two times they compare are the two locks I compare in my DARM plot: the blue "old" trace from April 6, 60W, and the orange "new" trace showing now at 60W. The beam position has changed, and the heat map shows that we are heating the ITMX point absorber more than we did previously.

If the spot has moved closer to a point absorber, this would explain our increase in jitter. If the spots on the test masses are shifting, this could also affect PIs like the 80 kHz that may be spot dependent. A spot position change could also aggravate the point absorber to where the radius of curvature and substrate lensing would change enough that our mode matching solution via the ring heaters would no longer be sufficient. We only have evidence that the spot has changed on ITMX, but there is a chance that it could have changed on the ETMs as well, where we know the 80 kHz acoustic mode is located. Unfortunately, we don't seem to have any good signals that could track this on the ETMs, so we are flying blind.

Overall, one of our goals (especially in powering down) is to get the IFO mode matched well enough that we can reduce frequency noise and be able to achieve a good level of squeezing. I think we should consider moving the spots on the test masses, especially ITMX. Those who remember, you might be thinking "we already tried this and saw no effect!" However, we have a different IFO now, and I think it is worthwhile to try moving further away from our point absorbers.

State of H1: Observing at 132Mpc

H1 has been locked for 17 hours and observing for 4 hours. Just rode out a 5.3 earthquake from Japan; otherwise a quiet evening.

Brina, Marissa

We noticed that there seems to be a daily drop in the BNS range by a few megaparsecs for about 10 minutes at around 17:00 UTC. I have found it most clearly since June 22, but there are a couple of times before that. 

I scrolled through the daily Lasso pages and found that two of the days (June 24 and 25) picked up the channel H1:SUS-ITMY_L3_OPLEV_BLRMS_P_3_10 as correlated with this dip (see this figure). On June 30 lasso picked up the channels H0:VAC-LY_TERM_M17_CHAN2_IN_{MA, COUNTS} and  H0:VAC-LY_CP1_PT101_DISCHARGE_PRESS_{MA/PSIG}.mean (figure). 

I plotted H1:SUS-ITMY_L3_OPLEV_BLRMS_P_3_10 and H0:VAC-LY_TERM_M17_CHAN2_IN_MA for June 22 - 25, 28, 30, July 6-8, and saw that both channels spike each day at the same time as the drop in range. 

I’ve attached examples from June 23 and July 7 showing the lineup of these channels at 17 UTC. I have not yet checked to see if these channels spike at other times causing dips in the range, but I haven’t noticed any other regular times with dips like these.

Just from looking at the summary pages, we weren't able to see anything noticeable in the strain spectrogram at these times. We made spectra comparing a few minutes before the range drop (16:55) and during the range drop (17:02) - see attached spectrum. We did this for a couple of times and don't see a huge obvious difference, but during the dip the spectrum does show slightly higher noise from around 20-200Hz.

Jenne, Naoki, Brina, Sheila

We put some offsets into the AS WFS loops, to check test if offsets in these loops caused by the OM2 change might be responsible for the change in jitter coupling that we see with heating of OM2.  We didn't see much improvement in the jitter coupling from adding pitch offsets to AS 72Q (SRM) or AS 36Q (MICH), but yaw moves made a big difference in the jitter coupling, as well as the low frequency noise.  

Times with om2 cold today :

• sqz off, AS72 Q Y offset +120 counts 21:49:17- 22:00:00 UTC (SRM yaw) 
• sqz on, AS 36 Q yaw 50,000 22:22:00-22:32 UTC (BS yaw)
• no offsets, sqz on, 20:00 UTC (calibration measurement time)

Gabriele ran a bruco for the first time here.  He also notes that the low frequency at this time looks like it could be scattered light. 

We are leaving offsets in AS 36Q yaw +35000, no offsets in AS72. 

TITLE: 07/13 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 135Mpc
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 6mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.04 μm/s
QUICK SUMMARY: Taking over from TJ and Oli. H1 has been locked for 13 hours, just returned to observing as of 23:02.

• All systems look good, range has improved thanks to today's commissioning efforts

TITLE: 07/13 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Commissioning
SHIFT SUMMARY:

15:00 Detector locked and observing for 5:02

16:25 Left Observing for Commissioning
    Alternating between NLN_CAL_MEAS and NOMINAL_LOW_NOISE for 5 mins each (71295):
    - 16:25:13 NLN_CAL_MEAS
    - 16:30:57 NOMINAL_LOW_NOISE
    - 16:35:21 NLN_CAL_MEAS
    - 16:41:21 NOMINAL_LOW_NOISE
    - 16:46:18 NLN_CAL_MEAS
    - 16:51:43 NOMINAL_LOW_NOISE
    
17:01 Commissioning done, back into NLN and Observing    

18:14 Out of Observing, Commissioning started
    - 19:22 CAL measurement started
    - 21:13 CAL measurement ended

23:00 Commissioning wrapping up. Interferometer has been Locked for 13:01.

Handing off to Ryan S.

LOG:

Naoki, Sheila

We revisted the alignment shifts of the OMC that we did yesterday morning, (71268) with a cold om2 today.  Yesterday we saw that we were able to reduce the jitter coupling measured by exciting the IMC PZT, but that this didn't improve the peaks caused by ambient jitter in DARM (see Brina's comment).  So, today we didn't bother with the injections on the PZT, but moved the QPD offsets and looked at the jitter peaks in DARM and the coherence with the IMC WFS DC channels.  We weren't able to reduce the jitter peaks by much with om2 cold, we moved both OMC QPDs in both pitch and yaw to explore the alignment space, we found that we could make the jitter peaks very slightly better at the cost of 10% loss of optical gain, or in other parts of the space we started to saturate the suspensions when we moved to where the jitter peaks were very slightly reduced.  None of these slightly reduced peaks gave us jitter as low as we had with hot om2.  We've returned the offsets to the original offsets, found before we turned on the TSAMs.  This has restored the optical gain to what it was before the TSAMs was on. 

I updated the swept-sine frequency vectors used in the calibration swept-sine DTT templates. They now match what is used in LHO's simulines configuration.

Frequency points changed (Hz): 

10.01 -> 10.11
59.78 -> 64.78
180.5 -> 175.5

DTT templates are located at /ligo/groups/cal/H1/ifo/templates. pyDARM cmd tools will automatically use these templates on future runs.

While Livingston is down, we took the opportunity to take some measurements to verify this alog by Elenna (71149). We moved out of Observing into Commissioning and alternated between NLN_CAL_MEAS and NOMINAL_LOW_NOISE, switching between them every 5 minutes and going through three cycles of this.

Times (UTC):

 - 16:25:13 NLN_CAL_MEAS
 - 16:30:57 NOMINAL_LOW_NOISE
 - 16:35:21 NLN_CAL_MEAS
 - 16:41:21 NOMINAL_LOW_NOISE
 - 16:46:18 NLN_CAL_MEAS
 - 16:51:43 NOMINAL_LOW_NOISE

DARM coherences after OM2 was turned off and is now cold: https://ldas-jobs.ligo-wa.caltech.edu/~gabriele.vajente/bruco_DARM_1373284789_COLDOM2/ 

It looks like the low frequency noise has now higher than usual coherence with:
DHARD_Y: https://ldas-jobs.ligo-wa.caltech.edu/~gabriele.vajente/bruco_DARM_1373284789_COLDOM2/ASC-DHARD_Y_IN1_DQ.html
MICH: https://ldas-jobs.ligo-wa.caltech.edu/~gabriele.vajente/bruco_DARM_1373284789_COLDOM2/LSC-MICH_OUT_DQ.html
PRCL: https://ldas-jobs.ligo-wa.caltech.edu/~gabriele.vajente/bruco_DARM_1373284789_COLDOM2/LSC-PRCL_OUT_DQ.html

and adding jitter coherence for reference: https://ldas-jobs.ligo-wa.caltech.edu/~gabriele.vajente/bruco_DARM_1373284789_COLDOM2/PEM-CS_ACC_PSL_TABLE1_X_DQ.html