MID-SHIFT SUMMARY: After losing lock, for reasons not apparent to me, there was some difficulty getting re-locked that included initial alignment (PRMI wouldn't lock), diff VCO woes, OMC locking on wrong mode and Jenne helping with wait times for ASC loops. Finally back to NLN at 20:00UTC. Wind is ≤5mph. EQ Sei is ≈t .28µ and µSei is ≈.12µ.
Following on from Hugh's alog entry (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=22883) about the reference cavity temperature and HEPI hitting its software limit ... Attached are two plots of the reference cavity temperature: an in the loop measurement (H1:PSL-FSS_DINCO_REFCAV_TEMP) and out of loop measurement (H1:PSL-FSS_DINCO_REFCAV_TEMP_OOL). The coefficient of thermal expansion for Corning 7940 is 0.52E-6 / degC. For the ~0.01 degC change this corresponds to a length change in the reference cavity of 5.2 nm, or a dL/L of 2.6E-8. Assuming the equivalent dL/L for HEPI is 6.3E-8 (250E-6/4000) then the temperature change doesn't fully explain why HEPI hit its limit. However temperature regulation of the reference cavity wouldn't hurt, particularly if done at a point higher than room temperature. The hardware is already there, modulo a small change to bring the heater front end model to reflect the installed cabling - a post observing run task.
TITLE: Nov 6 DAY Shift 16:00-00:00UTC (08:00-04:00 PDT), all times posted in UTC
STATE Of H1: Observing
OUTGOING OPERATOR: Patrick
QUICK SUMMARY: IFO is in Observing @ ≈80Mpc. Eq sei bands are all in the .2micron range. µSei is around .2µ. Wind is 0mph. All light appear to be off in E, M, CS & PSL. CW injections are running. Cal lines are running. Livingston is up and running. Quite 90 blends being used.
TITLE: 11/06 [OWL Shift]: 08:00-16:00 UTC (00:00-08:00 PDT), all times posted in UTC STATE Of H1: Locked. Observing @ ~ 80 MPc. SHIFT SUMMARY: Locked and observing entire shift. Possible EPICS freeze. SUS ETMY saturations. INCOMING OPERATOR: Ed ACTIVITY LOG: 10:07 - 10:16 UTC Stepped out of control room SUS E_T_M_Y saturating (Nov 6 09:02:02 UTC) SUS E_T_M_Y saturating (Nov 6 09:02:04 UTC) Current time: Nov 6 10:00:00 UTC SUS E_T_M_Y saturating (Nov 6 10:41:05 UTC) Current time: Nov 6 11:00:00 UTC SUS E_T_M_Y saturating (Nov 6 11:26:53 UTC) Current time: Nov 6 12:00:00 UTC Current time: Nov 6 13:00:00 UTC Current time: Nov 6 14:00:00 UTC SUS E_T_M_Y saturating (Nov 6 14:22:30 UTC) SUS E_T_M_Y saturating (Nov 6 14:22:32 UTC) SUS E_T_M_Y saturating (Nov 6 14:22:35 UTC) Current time: Nov 6 15:00:00 UTC SUS E_T_M_Y saturating (Nov 6 15:46:04 UTC) SUS E_T_M_Y saturating (Nov 6 15:46:07 UTC)
~ 13:55 UTC Noticed brief flatline in striptools. Doesn't appear to have affected anything.
Have remained locked and in observing. Rode through what appears to be two small earthquakes.
TITLE: 11/06 [OWL Shift]: 08:00-16:00 UTC (00:00-08:00 PDT), all times posted in UTC STATE Of H1: Observing @ ~ 81 MPc. OUTGOING OPERATOR: Cheryl QUICK SUMMARY: From the cameras the lights are off in the LVEA, PSL enclosure, end X, end Y and mid X. I can not tell if they are off at mid Y. Seismic in 0.03 - 0.1 Hz band is between .007 and .03 um/s. Seismic in 0.1 - 0.3 Hz band is between 0.08 and 0.3 um/s. Winds are less than ~ 5 mph. ISI blend filters are on Quite_90.
Title: Ops Eve Shift Summary, 00:00UTC to 08:00UTC1(6:00PT to 23:59PT), all times UTC
State of H1: locked in Observe 12+ ours, Range is 81Mpc
Incoming Operator: Patrick
Shift Summary: quiet evening with good range
Shift Activities:
- 00:07:01UTC ETMY saturation
- 00:09:00UTC, Kyle called and reported that he and Gerardo were back from x28 port
- 01:08:23UTC ETMY saturation
- 01:08:26UTC ETMY saturation
- around 01:21UTC, earthquake arrived
Time: Fri Nov 06 01:09:55 UTC 2015
Location: 87km SSW of Nikolski, Alaska; LAT: 52.3, LON: -169.5
Magnitude: 5.5
- 03:57:03UTC ETMY saturation
- 04:19:40UTC ETMY saturation
- 04:40:56UTC ETMY saturation
Cheryl emailed me to say that the durations shown by GWIstat were incorrect. I looked and it turns out that GWIstat (and also gwsnap) got restarted by Condor a few times today, for reasons which are not yet clear. Each time it restarts, the duration counters for LHO and LLO get reset to zero, since the program doesn't currently have a way to look back in time to set the duration properly. But I have added a little code to add a greater-than sign on the duration when the program restarts, until the status changes, so at least there will be a visual indicator that the duration shown is just a lower bound.
[JeffK, Jenne]
More thought required, but here is a plot overlaying the power recycling gain as measured by PD DC powers, and the optical gain as measured by the calibration lines. Both of them are normalized, so that we are looking at percent changes rather than absolute values. The calibration line data is taken from Sudarshan's aLog 22908.
I noticed that the End station temperature had just started to climb rapidly so I checked out the chilled water system and found CWP1 tripped off. Since this pump tripped earlier in the week with no obvious reason I elected to start the alternate pump CWP2. The VEA temperature is returning.
Marie at LLO has finalized the calibration / conversion from the A2L gain to actual beam spot position, and posted the LLO results at aLog 22426. I have downloaded the updated code, and redone the plots of LHO results, and it's still clear that our beam positions change very little lock-to-lock.
Again, the color of the spot indicates the length of time since the power-up: blue is a cold IFO, and more pink is a warmer IFO.
TITLE: Nov 5 DAY Shift 16:00-23:00UTC (08:00-04:00 PDT), all times posted in UTC
STATE Of H1: Observing
SUPPORT: N/A
LOCK DURATION: Entire shift
INCOMING OPERATOR: Cheryl
END-OF-SHIFT SUMMARY: IFO locked the entire shift.(currently 74.1Mpc) The winds picked up to over 20mph twice but for short periods. GraceDB Ext Not system continues its vener ending pass/fail cycle. Sei and µSei remain the same. Handing off to Cheryl.
ACTIVITY LOG:
16:30 Chris called to inform me that he would be heading out to do the aluminium stripping on the X arm
17:07 Joe out to join Chris on the Xarm
17:10 Karen into CS mechanical room to swiffer
17:15 Increase in EQ band x-axis to .1µm/s due to a pair of earthquakes around New Guinea and Timor
17:30 Winds increasing to ≤20mph
18:17 Joe back temporarily to get necessaries then heading back out. Chris is back and out to an appointment
19:57 Joe back from x-arm, for now.
21:00 X-arm crew back out to work
21:34 Noticed a slight downward trend in range starting about 2 hours ago. µSeism is around .3 mocrons
21:38 Kyle asked about driving forklift from shipping and recieveing area of OSB to woodshop for loading a generator to bring to X-2-8. I recommended that he doesn’t do that at this time as we are in coincidental observing mode with Livingston. I will contact him if we should break lock.
21:44 Got the OK from Landry to move the green forklift from LSB for the abovementioned task.
21:48 John W informed me that they were fixing the FMCS computer and that I was going to get some errors and alarms. ie; CS temperature is low (Nov 5 21:48:23 UTC)
22:59 Range is back up to 80Mpc
23:08 Joe reported back from X-arm. Chris will follow shortly.
23:30 Dave Barker will be going into the MSR to change tapes.
MID-SHIFT SUMMARY: Nothing big to report except for some ETMY glitches (usual). the wind picked up for a bit, around 20mph, but it’s starting to die down. Also, one GraceDB External Notification script failure and recovery as I’m writing this. (that I’ve noticed).
I have posted the latest LHO calibration uncertainty plots. I have reduced our kappas' uncertainty to 1% in mag and 0.5 degrees in phase. We are now limited by our measurements. I believe that our "statistical uncertainty only" plots are underestimating error. This is because the systematic error that remains in our measurements is ignored when we consider only the uncertainty bars. One way to combat this underestimation is to not fit our systematic to the final weighted mean of all our measurements, but instead fit to each of our measurements and take the std of our remaining systematic errors as our total systematic error. This ought to fix the fact that I was ignoring remaining systematic errors in our "statistical uncertainty only" plots. Plots 1-4 show nominal O1 model mag and phase uncertainty (the statistical uncertainty and systematic error summed in quadrature). Plots 5-8 show the systematic corrections model mag and phase uncertainty (statistical uncertainty only). I believe these are currently underestimated. Plot 9 is the comparison of the nominal O1 calibration response function to the systematic corrections model I make. (The red line is the systematic correction model, the dashed lines are the associated uncertainty)
Several follow up comments:
- On describing I would say it differently, plots 1-4,
(1) 05-Nov-2015_Strain_Uncertainty_Magnitude.pdf
(2) 05-Nov-2015_Strain_Uncertainty_Phase.pdf
(3) 05-Nov-2015_Strain_Uncertainty_Squared_Magnitude_Components.pdf
(4) 05-Nov-2015_Strain_Uncertainty_Squared_Phase_Components.pdf
are not the "nominal" uncertainty. These are the uncertainty if we incorrectly add systematic errors with statistical uncertainty in quadrature (i.e. implying we don't know the sign of systematic error and/or that they don't affect the mean of the Gaussian distribution, which we do and we know does). The reason we show these is to show how the uncertainty has traditionally been quoted, given the level of sophistication search algorithms had been able to handle. It's also much each to make a "single number" statement from this curve, which is what most people want so they can discuss the uncertainty colloquially.
Now that parameter estimation groups are interested in greater detail (i.e. have asked questions like "what do you *really* mean by '10%'??"), and we have solid handles on some of our systematic errors, we can offer an alternative display of the statistical uncertainty ONLY, namely plots 5-8,
(5) 05-Nov-2015_Strain_Uncertainty_Magnitude_Systematics.pdf
(6) 05-Nov-2015_Strain_Uncertainty_Phase_Systematics.pdf
(7) 05-Nov-2015_Strain_Uncertainty_Squared_Magnitude_Components_Systematics.pdf
(8) 05-Nov-2015_Strain_Uncertainty_Squared_Phase_Components_Systematics.pdf
and then display the resulting affect on the mean in plot 9,
(9) 05-Nov-2015_Strain_Uncertainty_Systematics_vs_Nominal_Residuals.pdf
Black solid shows a zero mean error on the response function, with statistical uncertainty and systematic error incorrectly added in quadrature, shown in black dashed. Red solid shows the mean, corrected by the systematic errors, with the correct statistical uncertainty surrounding it.
- The f > 1 [kHz] statistical uncertainty is more ill-defined than reported. We simply don't have the measurements up there to confirm such small precision, so Craig, for the time being, has merely cut off the uncertainty at the last frequency sweep's data point (~900 [Hz]) and used that as the default value out to the limit of the frequency range. As such, the uncertainty appears to be limited by the 1% / 0.5 [deg] statistical uncertainty of the calibration lines, translated from lower-frequency (~330 [Hz]) because that's we scale of the overall optical gain in the sensing function. While we don't expect the uncertainty to be much larger at high frequency, we simply don't have any quantitative upper bound. Nor do we have any idea what kind of systematics dragons tharr be. As such, I suggest we continue take the f > 1 [kHz] uncertainty with a grain of salt.
O1 day 48
model restarts logged for Wed 04/Nov/2015
2015_11_04 11:16 h1nds1
Unexpected restart of nds1, maybe due to overloading and/or testpoint activity.
TITLE: 11/04 Owl: 8:00-16:00 UTC STATE Of H1: Observing @ ~80 MPc. SHIFT SUMMARY:It ended well... SUPPORT: ACTIVITY LOG: H1 was locked when I came in. Lost lock about 11:00 UTC. Flashes weren't great during DRMI, so after 15 minutes of waiting for DRMI, then another 15 minutes of PRMI, all with low or no flashing, I did an initial alignment. After that DRMI was still rough. Back to observing at 14:00. 15:00 LLO called to say they were doing some environmental measurements, but not going out of low noise for a while.
In light of the violin mode stuff over the weekend, I wanted to make sure we aren't going to be caught unawares by other harmonics ringing up.
We have paid considerable attention to damping the fundamentals and second harmonics of the violin modes, but in general we leave the higher harmonics undamped. (We have had some isolated cases in which we have had to temporarily apply damping to high harmonics; see, e.g., LHO#18599).
I checked the heights of the third harmonics during the first long lock (25 hours long) that we had after the power outage. I chunked the DCPD sum timeseries into 1000 s segments and then took ASDs of each. To identify the violin modes, I simply looked for peaks in the DCPD spectrum that were higher than some threshold above the noise (in this case, the noise floor is about 1×10−7 mA/Hz1/2, and the threshold I chose was 5×10−6 mA/Hz1/2). This resulted in 25 peaks being identified. For each ASD, I integrated under each peak to get an rms mode amplitude. Since the violin modes are anharmonic, I believe that these peaks (which range in frequency from 1456.18 Hz to 1484.67 Hz) are truly third harmonics, rather than upconverted first harmonics (which range from 498 to 509 Hz, and hence we would expect upconversion to appear from 1496 to 1527 Hz).
All 25 peaks appear to be ringing down, with time constants on the order of 2×105 s (≈50 hours). I fitted each ringdown to an exponential, which resulted in Qs ranging from 0.55×109 to 1.28×109. [For similar results on lower-order mode Qs, see, e.g., Keiko's measurements on L1 IY.]
Similarly, we don't have any damping on the second harmonics of the ITM violin modes. Here, we see 16 modes, and all of them ring down, with Qs ranging from 0.72×109 to 1.43×109.
For a discussion on the behavior of some of the ETM second harmonics after the power outage, refer to Nutsinee's alog.
For fourth and fifth harmonics, there are fewer traces which show clear ringdown; many appear to be complete garbage. Not clear why.
Anyway, for the fourth harmonics, Qs range from 0.6–1.1×109, and for the fifth harmonics, Qs range from 0.6–0.9×109.
Today, I discovered that on all of the HXTX Aux Ch screens (SUS_CUST_HXTX_MONITOR_OVERVIEW.adl) each of the M3 stage indicator lights are COPY/PASTEs of the M2 ones. The channel values are all reading the appropriate channels, but the visual is incorrect for M3. See attached.
Need to fix...
Disregarding my "HXTX" references above which should read "HXTS", I've fixed the error in the screen and committed it to SVN.
Screen address:
/opt/rtcds/userapps/release/sus/common/medm/hxts/SUS_CUST_HXTS_MONITOR_OVERVIEW.adl