H1 has been locked since about 3:30pm with a range around 75Mpc (except for drop due to commissioning).  Evan continues DARM work with H1.  L1 was up for an hour, but is back down currently.

Minimal glitches on H1.

I believe that SRM M3 saturations caused the lockloss this afternoon that happened when the earthquakes hit us. 

In the attached plots, the data are the same, but one is zoomed in on the lockloss time and the other is not.  From the 2nd attachment ("SRMsat_longPlot.png") you can see that individual coils saturate at various times leading up to the lockloss, but we are still locked.  The first plot shows that at about 58.9 seconds, all 4 coils are simultaneously saturating (the horizontal black cursors are at +-132k).  60 msec after the first simultaneous saturation, ASAIR indicates that we have lost lock. 

Sheila saw this kind of pattern for PRM a few days ago, and fixed it by improving the offloading from PRM's M3 -> M1 (alog 21276).   I think that we should do something similar for SRM, and maybe be more robust during times of high ground motion. 

SudarshanK, GregM, RickS

The SenseMon range shows an increase in range from about 63 Mpc to about 75 Mpc from the previous to the current lock stretch.  JeffK suspected this is the result of a change in the sensing function.

GregM used the SLM too to generate 60-sec FFTs of the calibration lines and we calculated the time varying parameters (see T1500377) using these data to assess changes in the sensing function.

The resulting kappa_C, the sensing function variation, as well as f_c, the coupled cavity pole frequency, are shown in the first plot attached below.  The second plot shows the SenseMon range over the past 12 hours with the step in the IR between the current lock and the previous lock.

It seems that the change in sensitivity is indeed the result of variatioins in the sensing function which are tracked by kappa_C.

Note that we are not currently compensating for changes in the sensing function, but we plan to be soon, when the GDS calibration is up and running (and compensating for kappa_C).

SudarshanK, RickS

Now that "DeltaL_Ext" is calibrated, we can compare the estimated Pcal line heights (in meters) using the calibrated Pcal Rx and Tx PD signals with the DeltaL_Ext calibrated line heights.

There are known errors in DeltaL_Ext arising from delays, filter pre-warping, OMC DCPD poles, etc. that are not accounted for in this quick look.

The ratios between the Pcal calibrations and the DeltaL_Ext calibration for the 3001.3 Hz line (injectetd at Xend) and the 1083.7 Hz line (injected at Yend) are given in the table below.

So with a quick look the DeltaL_Ext calibration seems to agree with Pcal at the ~10% level at 3 kHz.

DTT plot attached below.

I committed all the OBSERVE.snap and a few uncommitted safe.snap files for LSC LSCAUX ASC ASCIMC OMC OAF  & TCSCS noting that in the userapps these safe.snap files are h1lsc_safe.snap for example.  Obvious to most of us but for the psl files...:

Similar for the PSLDBB PSLFSS PSLISS & PSLPMC except I found in the USERAPPS area in each of the DBB FSS ISS & PMC subfolders of the PSL area, both a safe.snap and a h1psliss_safe.snap file committed to the svn.  And the safe.snap softlink trom the frontend area, pointed to the h1psliss_safe.snap file (as it should.)  And the safe.snap and the h1psliss_safe.snap files in the USERAPPS area were not the same==> its even confusing as to how to explain except safe.snap in one area does not equal the safe.snap in the other.  And...so I removed the safe.snap from the svn.  The saving grace is that these files where a couple years old and much older than the named safe file.

There might be a few more of these that Betsy and I need to deal with in this manner.  On going.

• TITLE:  9/11 EVE Shift:  23:00-7:00UTC (16:00-0:00PDT), all times posted in UTC

• STATE Of H1: Shift started in Commissioning (Evan working on DARM) with H1 newly locked (30min) with a range of ~75Mpc.

• OUTGOING OPERATOR: TJ was on DAY shift.

• QUICK SUMMARY:  4.5Magnitude earthquake in Mexico started dying down around the time I arrived (low freq still slightly elevated).  Winds under 10mph.  TJ thought LLO was down for PEM injection work.
  

Log:

Times in UTC (PST)

• 1500 (800) Locked at Nominal Low Noise when I arrived
• 1542 Chris/Joe will be heading down the arms to do more seam sealing on the beam tube enclosures.
• 1616(916) Kyle will be breifly going past the card reader in the CS, driving around Corner Station to pick up nitrogen tanks, and then going to the X28 port.
• 1621 Taken out of Observe to allow for Kyle's driving, beam tube enclosure sealing, and Betsy doing SDF work
• 1630 Betsy done
• 1754 (1054) Dick G to the optics lab
• 1920 (1220) Jodi to MX
• 1948 Jodi back
• 2027 (1327) Joe/Chris done
• 2108 (1408) Evan doing some DARM reshaping, out of Observe
• 2110 Bubba down the Xarm to check on earlier work
• 2130 Bubba back
• 2138 Lockloss (May have been due to a few earthquakes. There was a 5.2 in Mexico and a 5.4 in Japan that should have arrived at similar times.)
• 2258 (1558) Evan starting DARM work again.

Re 21309 (HEPI) and 21346 (ISI,) I've made another change to the SDF OBSERVE.snap file TABLE and the current Monitor Select.

Even though all the HEPIs and the HAMISIs will have no differences between locks (Platform Trip and Reacquire,) which means there is always no expected differences for ALL channels, meaning the Guardian Touched DO NOT MONITOR list could be retained with the OBSERVE.snap file and the ALL MONITOR SELECT button could be used to monitor everything, since this is not the case for all SDFs, we will not do this for the HEPIs or HAM ISIs.

So for the HEPI and HAM ISIs, the OBSERVE.snap file has no NOT MONITORED channels and the MONITOR SELECT is set to MASK---Unlike the BSC-ISIs which all have 12 NOT MONITORED channels, the SETPOINT_NOW value which will change everytime those platforms trip and guardian reisolates them.  Changes have been committed.

J. Kissel, C. Biwer

At the request of Betsy (LHO aLOG 21303), I asked Chris to work with Duncan to solve that ODC state vector for hardware injections was reporting that the CAL-INJ_HARDWARE bank has been reporting the wrong status since Eric and Cheryl turned off the digital limiter on the filter bank (LHO aLOG 21198). Chris has succeeded admirably -- we merely needed to update the hexidecimal value against which the filter status is compared in the front-end ODC. We've 
(1) Changed the H1:CAL-INJ_ODC_HARDWARE_CTRL_EQ channel to be 0x1602 (instead of 0x3602) -- and the associated ODC bit went green, and subsequently the summary bit
(2) Accepted the change in the OSEBERVE.snap file in the SDF.
(3) Briefly switched to the SAFE.snap file, and accepted it there, then reverted back to using the OBSERVE.snap
(4) Copied the OBSERVE.snap over to the userapps repo, added, adn committed it there
(5) Removed the original OBSERVE.snap, and replaced it with a softlink to the userapps location,
jeffrey.kissel@opsws2:/opt/rtcds/lho/h1/target/h1calcs/h1calcsepics/burt$ ls -l OBSERVE.snap 
lrwxrwxrwx 1 jeffrey.kissel controls 65 Sep 11 14:57 OBSERVE.snap -> /opt/rtcds/userapps/release/cal/h1/burtfiles/h1calcs_OBSERVE.snap
jeffrey.kissel@opsws2:/opt/rtcds/lho/h1/target/h1calcs/h1calcsepics/burt$

Attached are screen shots of the before and after.

Next up -- an updated MEDM screen...

Chris S. Joe D.-40% each.

This week the guys had to cut 2 more of the 25# rolls into strips and punch holes. They were able to install strips on the top of 120 meters of enclosure making a total of 2280 meters completed.

Here's a summary for Operations regarding notification of critical calibration line failures during O1:

- PCAL LINES @ 3001.3 PCALX, 36.7Hz and 331.9Hz PCALY - If these "die" (such as the laser or photodiode fails), the INTENT BIT WILL BE DROPPED because they are going to be in the DIAG_CRIT guardian (TJ working on it).  If someone changes the frequency or other medm setting related to the lines, SDF will flag red and the INTENT BIT WILL BE DROPPED.

CALL PCAL IMMEDIATELY if this happens.

- DARM CAL LINE @ 37.3Hz- The only failure mode of this line will be if someone changes a setting in medm - if so, the INTENT BIT WILL BE DROPPED. 

MEDM can be found under white SITEMAP/CAL/DARM Calib screen.

REVERT changes to make SDF green and make an alog.

- ESD LINE @ 35.9Hz - The only failure mode of this lines will be if someone changes a setting in medm - if so, the INTENT BIT WILL BE DROPPED. 

MEDM can be found under ETMY SUS from SITEMAP little purple screen near bottom of screen column called L3 CAL LINE (SUS_CUST_QUAD_L3_CAL_LINE.adl)

REVERT changes to make SDF green and make an alog.

- HARDWARE INJECTIONS - MEDM can be found under SITEMAP/CAL/HWINJ CTRL screen but still needs some of work, but there are a few fields there which we will add instructions for after it is working.  The CW injection signal is the one that flags red in the CDS H1CALCS EXC bit.  It has been "off" since Sept 8th and Dave is working on it.  GRB alert notices being late is also "being worked on".  To be continued...

All work is done (for now) so we are back in Observe

The IFO is locked in Nominal Low Noise, but we are not in Observing mode due to beam tube seam sealing and a few various other trips around the site.

Highly related: alog 21234

Conversion coefficients to obtain the equivalent beam rotation at the periscope from IMC WFS signals were measured at around 20Hz while IFO was operating in low noise (see subentry for details):

There could easily be 10 or 20% error but this cannot be off by an order of magnitude.

Note that the PIT to YAW and YAW to PIT coupling in the sensing are not small at all. PIT to YAW sensing coupling is about 0.6 for WFSA and 0.9 for WFSA, while for YAW to PIT the numbers are 0.5 for WFSA and 0.4 for WFSB. (This is not surprising as the WFS quadrant gains are fishy: alog 20065). If we need to evaluate PIT and YAW jitter separately, it's somewhat better to use WFSB for PIT and WFSA for YAW.

The attached shows WFSB PIT and WFSA YAW, already calibrated to radians using the above table (assuming that WFS response as a sensor is flat), and OMC DCPD in full lock. There are two lines injected to Peri PZT, @20Hz for YAW and 22.1Hz for PIT. The excitation voltage is the same for both, but due to the fact that peri mirror is tilted by 45degrees in PIT, beam deflection in YAW is sqrt(2) smaller than PIT.

Taking this into account, PIT to DCPD coupling is a factor of 7.5 smaller than YAW coupling. Looking at the peaks, indeed there are peaks in WFSB PIT, most notably at 280Hz, that are not present in DCPD even though the hight was as large as  annoying twin peaks at 315 and 350Hz, and this is consistent with the smaller PIT coupling.

The attached also shows IMC trans SUM. PIT peak (22.1Hz) is much larger than YAW (20Hz) even you take a factor of sqrt(2) into account. This is probably due to the fact that MC WFS offset for PIT is much larger than YAW. Even then, PIT coupling is smaller. This is one of several things that show that this cannot be a simple jitter AM conversion by MC.

Among many calculations that could be done, I'll probably convert the input beam jitter to the beam jitter on OMC.

Out of Observing due to some SDF work and a few maintenance items.

The raw minute SSD RAID has been rebuilt, and h1tw0 is now writing raw minute trend data to it's disk.  Since data from April 14 to present was lost, we will evaluate if data recorded from h1tw1 can be used to fill in the gap.

Jeff, Darkhan, Sudarshan, Craig, Kiwamu,

We have updated the calibration filters in CAL-CS with the latest filters.

With a Pcal sweep measurement, we have confirmed that the current calibration is accurate within 10 % in magnitude and 5 deg in phase.

Calibration on the front end side is done.

(Verification measurement)

The above screen shot shows a measured transfer function from displacement estimated by Pcal Y to displacement estimated by CAL-CS. They agree within +/- 10 % in magnitude and +/- 5 deg in phase all across the frequency band we swept. Note that one data point at 10 Hz showed magnitude that is slightly above 10%, but this was not repeatable and therefore we don't think it is a reliable data point. We measured the same transfer function three times within the same lock stretch and saw the magnitude changing to a value between 0.85 and 1.1 at this particular frequency point. We are guessing that this is due to a bounce mode confusing our measurement.

Also, even though the coherence was high all across the frequency band, the data points below 30 Hz seemed to change in magnitude in every sweep. So we increased the integration time from 3 sec to 6 sec which seemed to improved the flatness.

The optical gain was adjusted by measuring the sensing function with a Pcal sweep within the same lock stretch. This gave me a 341 Hz cavity pole (which is the same as two nights ago, alog 21352) and an optical gain of 8.834e-7 meters/counts. Both the parameters are now loaded into the CALCS foton file and enabled.

(Phase correction)

Sudarshan will make a separate alog on this topic, but a trick to get this beautiful plot was to properly incorporate the know time delays. Based on our knowledge, we have included a 115 usec = (41 + 61 + 13 usec) time delay. If we did not remove the delay, the phase would have been off by 40 deg at 1 kHz.

(An extra measurement)

Independently of the calibration validation measurement, we did a simple measurement -- check the binary range with and without the calibration lines. Here is the relevant time stamps:

• Sep-11-2015 1:45:25 UTC, calibration lines turned off, not exctiations, fully locked at NOMINAL_LOSWNOISE
• Sep-11-2015 1:59:06 UTC, calibration lines turned back on.
• Sep-11-2015 2:50:03 UTC, unlocked

We will check the range later.

Dan, Evan

This evening we made a qualitative study of the coupling of beam jitter before the IMC into DARM.  This is going to need more attention, but it looks like the quiescent noise level may be as high as 10% of the DARM noise floor around 200Hz.  While we don't yet understand the coupling mechanism, this might explain some of the excess noise between 100-200Hz in the latest noise budget.

We drove IMC-PZT with white noise in pitch, and then yaw.  The amplitude was chosen to raise the broadband noise measured by IMC-WFS_A_I_{PIT,YAW} to approximately 10x the quiescent noise floor.  This isn't a pure out-of-loop sensor, and since we were driving the control point of the DOF3 and DOF5 loops of the IMC alignment channels we will need to work out the loop suppression to get an idea of how much input beam motion was being generated.  Unfortunately we don't have a true out-of-loop sensor of alignment before the IMC.  We may try this test again with the loops off, or the gain reduced, or calibrate the motion using the IMC WFS dc channels with the IMC unlocked.  Recall that Keita has commissioned the DOF5 YAW loop to suppress the intensity noise around 300Hz.

The two attached plots show the coherence between the excitation channel (PIT or YAW) and various interferometer channels.  The coupling from YAW is much worse: at 200Hz, an excitation 10x larger than normal noise (we think) generates coherence around 0.6, so the quiescent level could generate a few percent of the DARM noise.  Looking at these plots has us pretty stumped.  How does input beam jitter couple into DARM?  If it's jitter --> intensity noise, why isn't it coherent with something like REFL_A_LF or POP_A_LF (not shown, but zero)? 

The third plot is a comparison of various channels with the excitation on (red) and off (blue).  Note the DCPD sum in the upper right corner.  Will have to think more about this after getting some slpee.