Following up an earlier report on narrow lines in early ER7 data ("ER7A"), attached are spectra and a longer list of lines found in the 5-2000 Hz band
from examining an inverse-noise-weighted average spectrum over 149 hours of full-ER7 DC-readout data, using 30-minute Hann-windowed FScan SFTs.

The overall spectrum is similar to before, but the additional data reveals more structure. Here are highlights and lowlight of apparent changes:

 The bounce modes are better suppressed in the latter part of the run.
 A comb with 0.1698-Hz spacing is now visible in its 41st through 59th harmonics
 There is a newly apparent comb-on-comb structure with a fine spacing of 0.0884 Hz attached to a comb of 
76.9426-Hz lines. Only the clusters up to the 3rd harmonic of 76.94 Hz are labeled on the spectra, but one
can still see indications of the comb-on-comb up to at least the 12th harmonic at 923 Hz.
 Something I overlooked before is that the OMC dither lines at 1675.1, 1700.1, 1725.1 and 1750.1 Hz are prominent on 
top of their induced up-conversion. This is in contrast to what I usually see in L1 data, where the dither lines
themselves are servoed to near zero and are barely visible in the up-conversion they create.
 In addition to the previously noted combs of 16 Hz and 64 Hz harmonics, one can now see a very sporadic
set of 8-Hz lines. The more prominent ones are marked on the spectra and include 376, 552, 808, 1064, 1096,
1112, 1144, 1176, 1192, 1416, 1544, 1608, 1624, 1672, 1704, 1784, 1800, 1816, 1832, 1880 and 1896 Hz. 


Figure 1 - Spectrum 0-2000 Hz with labeled lines

Attachments: 
1 - Line list
2 - zip file with 27 sub-band spectra

As of COB today, we are on-schedule for the 4 day EX and EY vents.  So far no major surprises or issues.  Further dust monitor data to be posted later.

As per the schedule:

- The ISI's have been locked on both ETMx and ETMy.

- 2 CC witness samples have been pulled from each BSC9 and BSC10.

- The VE port work has finished at ETMy.

- The TMS work has finished at both stations.

- The ETMx debiasing has been completed (removed ~440 uRad of pitch mechanically at the suspension using the optical lever as the monitor.)  Bias is now at zero.  This is where commissioners should start looking for beams in a few weeks.  Yaw bias remains unchanged (and non-zero).

- Local charge measurements taken on ETMx with in-chamber equipment in prep for discharge procedures. 

- ESD feedthru swap has started.  Filiberto and Gerardo have pulled the flange and have it out and ready to reterminate with the new connector.

- Quick P and V TFs of ETMx show healthy suspension - Arnaud launched matlab overnight TFs of SUS-ETMx for further check.

First up tomorrow:

- Finish ETMx ESD feedthru work.

- Finish VE port work at ETMy.

- Move equipment to ETMy and Discharge ETMy.

- Close ETMy chamber.

I modified and restarted the BSC-ISI models to close ECR E1500245, E1500253 and E1500270. The changes are listed below, and described in details in the attached pdf.

* removed sts blrms calculation from the sensor correction of stage 1. The calculation is now done at the top level. A list of the new channel names is provided in the attached text files 

* Added a pick off of stage 1 CPS X and Y signals to feed the LSC model through PCIE senders on BS ITMX and ITMY

* Added a path from sus to the error point of the stage 1 controls to use for tidal feedback (mainly for LLO). 

18:02 PDT: DAQ restarted to sync with new INI files for BSC-ISI and OAF.

ISI was locked by Jim in the morning.

Before doing anything, EY alignment slider [PIT, YAW] = [142.0, -75.1], TMSY = [116.6, -20.0], EY OPLEV=[-39, -15]-ish.

Transitioned to laser hazard, moved EY such that the green return beam hits the center of the relf PD: EY [PIT, YAW]=[207.4, -75.1]

- Krytox on beam diverter in situ: Good.

Everything went well as per yesterday.

- QPD strain relief: Good-ish.

Unlike TMSX, it turns out that all QPDs were already equipped with a make-shift strain relief using stainless steel cable clamps, the same clamps used for fixing the cables on the TMS ISC table, but the cables were without kapton tubes. We decided to install the right strain relief anyway.

In the end, we were able to install the right ones on three out of four QPDs. As for the remaining one (Green QPDB), we weren't able to install it as the 1/4-20 Allen key to attach the PEEK strain relief to the QPD base would have interfered with the YAW knob of one of the QPD sled mirror holders (M102 in D1201458).  The stainless steel strain relief was left as is.

After this work, we checked if QPDs still work and they did (used green beam for the green QPDs and a flashlight for IR QPDs).

- TMS balancing: Good.

After the work, we checked the balace of the TMS table with the green light injected to the chamber. The vertical alignment was found to be already good and therefore we did not make any mechanical adjustment. Similarly, the horizontal was also good and giving an extra digital bias of +13 urad (resulting in -7.0 urad in OPTICALIGN_OFFSET) made the return beam well-centered on ALS-REFL_PD. So the balance is good.

After everything was done: EY slider [PIT, YAW] = [142.0, -75.1] (back to the original), TMSY = [116.6, -7.0], EY OPLEV=[-24, -31]-ish.

Seems like EY moves around by 15urad-ish both in  PIT and YAW, so TMS alignment could be only as good as 15urad-ish.

12:13 - Jason & P. King done in the PSL

12:20 - Karen & Christina to LVEA, cleaning HAM 6

12:40 - Travis, Betsy, Kate, Calum, Gary, Danny to EX

12:47 - Keita, Kiwamu, Corey - to EY, working on test masses

12:55 - Sheila to CS, EX, EY  restocking cables

12:57 - Fil, Gerardo, Kyle to EX, working on ESD Feed through and Vacuum

13:35 - Richard to EX

14:24 - Hugh to LVEA locking up HAM6 HEPI

14:42 - Richard, Fil, Gerardo back from EX

14:57 - Richard to LVEA talking to electrician

15:02 - Hugh out

15:10 - Richard, electrician out

15:28 - Keita, Kiwamu, Corey back from EY

15:30 - Keita to EX

15:51 - Keita back from EX

Laser Status:
SysStat is good
Front End power is 33.11W (should be around 30 W)
Frontend Watch is GREEN
HPO Watch is RED

PMC:
It has been locked 0.0 days, 4.0 hr 11.0 minutes (should be days/weeks)
Reflected power is 2.105Watts and PowerSum = 26.11Watts.

FSS:
It has been locked for 0.0 days 4.0 h and 11.0 min (should be days/weeks)
TPD[V] = 1.532V (min 0.9V)

ISS:
The diffracted power is around 8.14% (should be 5-9%)
Last saturation event was 0.0 days 1.0 hours and 15.0 minutes ago (should be days/weeks)
 

Because we don't have an interferometer, I've spent most of the last day trying to get a measurement that Anamaria suggested, a transfer function from the ITMX St2 ISI actuators to all the sensors associated with the optic. I'm stil trying to figure out the best way to do this, but I'm archiving my DTT templates in DCC T1500298. This measurement is intended to be a jumping off point, not commissioning data or used for controls design, so I thought the DCC would be the easiest place for people to find it. I'm only attaching pngs of only a few of the TF's because there are 51 channels and the xml's are 89mb a piece. I only have X,RY and RZ, I'll get the other dofs when I feel like I know better what I should be doing.

The measurements are all roughly the same, driving in the cartesian (IFO X,Y,Z etc) St2 actuators and looking at all of the ISI's sensors, the ITM's osems and the op lev. The ISI and Quad are in their nominal states (isolated/damped), I've change nothing in the controls scheme. For now I'm using a simple band-passed white noise, but I fully expect to have to do something like a swept sine because all of the sus sensors are just noise above a couple hz.

Rotational DOFs are within 6urads, Translational DOFs are within 30um.   Watchdog is tripped and should remain in that state.

Pcal calibration lines that were switched during ER7 as described in the alog #19026 has been reverted back to its original configuration and SDF monitors have been updated accordingly.

Now the calibration lines are at following frequencies:
PCALX at 33.1 Hz and 534.7 Hz
PCALY at 36.7 Hz and 540.7 Hz

The excitations are also turned off for now as pcal lasers have been switched off for venting.

Counts were taken using the Differential mode; the counts are for particles that are greater than the reporting size but less than the next reporting size. So a 0.3µ reporting size includes all particles that are greater than 0.3µ and less than 0.5µ.

J. Oberling, P. King

Summary

Attempted to test a spare TTFSS box that Peter had modified to see if it would increase the bandwidth of the FSS.  Unfortunately the FSS would not lock with the modified box so we installed the original and moved on.

Noticed that Front End (FE) diodes 3 and 4 were reading ~95.5% of ideal power (diodes 1 and 2 are still good).  This is odd as we just increased the diode currents 3 weeks ago.  We raised the current on diodes 3 and 4 to 52 A (from 51 A) and adjusted the temperature on both diodes to 18 °C.  Power out of the FE is now 33.1 W.  Will keep and eye on this.

Tweaked the beam alignment into the PMC using mirrors M06 and M07 and adjusted the position of PMC mode matching lenses L02 and L03.  PMC transmitted power is now 23.7 W and has a visibility of 90.7%

Since we swapped the FSS box we tweaked the FSS RefCav alignment.  FSS RefCav TPD is now reading 1.49 V and the RefCav has a visibility of 70.9%.  While doing this we began to suspect that the bottom mirror of the RefCav input periscope (PRS01) might be a source for the RefCav drift issues we've been dealing with.  It has been suggested that we move the bottom mirror from the periscope post and mount it directly on the table.  Will discuss this with the larger PSL group.

Details

TTFSS Box

As noted above, we attempted to test a spare TTFSS box that Peter had modified to hopefully give more bandwidth to the FSS.  Unfortunately the FSS would not lock with this modified box, so we reinstalled the original box and moved on.

Front End Diodes

Peter noticed that FE diodes 3 and 4 were reading ~95.5% of ideal power, which is odd as we just adjusted the currents on the FE diodes 3 weeks ago; they should not degrade this fast.  Diodes 1 and 2 are still reading 99% of ideal.  We raised the current on diodes 3 and 4 to 52 A from 51 A, and then tweaked the diodes' operating temperature to 18 °C from 19 °C.  The power out of the FE is now reading 33.1W.  We will keep an eye on this to see if this quick degradation continues.

PMC Alignment

We tweaked the beam alignment into the PMC as well as the position of the mode matching lenses in an effort to increase the power transmitted by the PMC.  We started by adjusting the lens positions to maximize transmitted power, and then adjusted the beam alignment.  The old and new lens positions, as read from the micrometers attached to the lens mounts, are:

• Lens L02
  • Old position: 11.3 mm
  • New position: 13.68 mm
• Lens L03
  • Old position: 4.15 mm
  • New position: 6.29 mm

We then proceeded to adjust the beam alignment into the PMC.  The majority of the adjustment was in yaw, pitch yielded very little improvement.  After alignment:

• PMC Trans
  • Old: 21.7 W
  • New: 23.7 W
• PMC Refl:
  • Old: 2.9 W
  • New: 2.1 W

This is a marked improvement, as previously the reflected power was 13.4% of the transmitted and now it is only 8.9%.  Finally we measured the PMC Refl PD (RPD) voltage while the PMC was both locked and unlocked to calculate the visibility:

• Locked: -0.143 V
• Unlocked: -1.54 V
• Visibility: 90.7%

FSS Alignment

Since we had changed out, then changed back in, the TTFSS box we tweaked the beam alignment into the FSS RefCav.  A small pitch tweak in the up direction on the top periscope mirror increased the RefCav TPD from 1.35 V to 1.5 V.  We then tried to tweak the bottom periscope mirror.  As soon as Peter inserted the adjustment knob into the pitch screw of the mount, the TPD dropped from 1.5 V to 1.34 V.  What's odd about this is that no adjustment was performed.  Simply inserting the adjustment knob caused the TPD to decrease.  What is even more odd is that Peter could not recover the alignment; could make it worse but could not get better than a TPD of 1.34 V, regardless of which periscope mirror was adjusted.  I then checked that the periscope mirror mounts were tight on the post, which they seemed to be.  All of a sudden Peter was able to recover the TPD back to 1.49 V with a small pitch tweak on the top periscope mirror.  Related?  Not sure...  At any rate, we started pressing and tapping on the bottom mount in various places to see if we could influence the RefCav TPD.  Turns out that we could slightly change the TPD, especially when manipulating the knob that secures the mount to the periscope post; when the same was done to the top periscope mirror mount and the periscope post, no change was observed.  We will discuss moving the bottom periscope mirror from the periscope post to the PSL table, in the hope that this would help alleviate the RefCav drift issue we've been seeing.

We then measured the RefCav RPD DC voltage and calculated the visibility of the RefCav:

• Locked: 75 mV
• Unlocked: 258 mV
• Visibility: 70.9%

Counts were taken using the Differential mode; the counts are for particles that are greater than the reporting size but less than the next reporting size. So a 0.3µ reporting size includes all particles that are greater than 0.3µ and less than 0.5µ.

Richard, Evan

Summary

It appears that the EY ESD bias was stuck at −430 V ever since the installation of the low-voltage driver in May. It became unstuck on 11 June, when Richard reset the driver.

Since we have always requested a positive bias for EY in the digital system (using SUS-ETMY_L3_LOCK_BIAS), this means that the reset on 11 June flipped the sign of the EY ESD actuation, causing the transition of DARM from EX to EY to fail (as TJ found).

To fix the transition, the EY bias is now requested to be negative in the digital system, thereby restoring the sign (but not the magnitude) of the true analog bias that we have had since 22 May. Of course, if the magnitude of the L3 actuation has changed, this will affect the accuracy of the calibration in the region dominated by the control signal.

Details

First, let us enumerate some of the mysteries surrounding the EY ESD:

1. After the low-voltage driver was installed (i.e., after 2015-05-22), we found that we had to flip the sign of the L3 actuation from positive to negative. This is despite the fact that both the low-voltage driver and the high-range driver supposedly have positive polarity at dc (so we should not expect to have to compensate for an analog sign flip).
2. After the low-voltage driver was installed, we found that the dc actuation strength of EY L3 was 50 times weaker than EX L3. We expect only a factor of 20×1.25 = 25. The factor of 20 comes from the difference in dc gain between the high-range driver and the low-noise driver (40 V/V versus 2 V/V). The factor of 1.25 is what Kiwamu had previously found necessary to match the dc strengths of EX L3 and EY L3 when they were both driven by the high-range drivers.
3. After the low-voltage driver was installed, the analog readbacks for the high-range driver (bias line and 4 quadrants) were stuck at −15000 ct.
4. After Richard reset the high-range EY driver for the charge measurements (2015-06-11, circa 21:00:00 UTC), there has not been a successful transition of DARM from EX to EY (although there have been only four trials, according to the summary pages).

We hypothesize that mysteries (1), (3), and (4) are explained by the EY ESD bias being stuck at −430 V between 2015-05-22 and 2015-06-11, and the driver's readbacks being nonresponsive. Mystery 2 is still unsolved.

When Richard went to EY on the 11th, he found the high-range driver putting out −430 V on all five lines, and the driver's analog readbacks were frozen at −15000 ct or so. According to him, this is a known failure mode of the driver's microcontroller. After he reset the driver, the analog readbacks became functional again.

The attached plot shows a trend of the analog readback of the EY ESD bias. It is stuck at about −15000 ct from 2015-05-22 (when the low-voltage driver installation was finished) to 2016-06-11 21:00:00ish UTC (when Richard reset the driver). The natural conclusion from this is that the EY ESD bias has been railed at −430 V between these two dates (even though we thought we were giving +380 V of bias).

I flipped the requested bias so that it is now (I think) −380 V, which is the most negative bias that can be requested from the driver when it is operating properly. I was able to transition control of DARM from EX to EY by hand following the steps in the guardian.

J. Kissel

In preparation for updating LHO's local copy of the QUAD model to receive all of Brett's new goodness (see LHO aLOGs 18987 and 18809), I've tagged the current SUS model that has been used for recent calibration studies for ER7. The tagged model lives here:
/ligo/svncommon/SusSVN/sus/trunk/Common/SusModelTags/Matlab/quadmodelproduction-rev7508_ssmake4pv2eMB5f_fiber-rev3601_fiber-rev7392_released-2015-06-09.mat.

Details:
--------
The tag was created using the following script:
/ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/tagsusdynamicalmodel.m  rev7650

The parameter set used,
/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/quadopt_fiber.m  rev3602
are the parameters that have been originally fit to match H1 SUS ETMY's M0-to-M0 (TOP to TOP) transfer functions, but used generically for all quads. It does *not* however include the "correct" frequencies of the violin modes as measured from H1 SUS ETMY (this is half the reason for the update).

The filters for local damping loops wrapped around the dynamical model were grabbed directly from the following foton filter file
/opt/rtcds/lho/h1/chans/filter_archive/h1susetmy/H1SUSETMY_1116978122.txt,
HOWEVER, *which* filter module was used and the damping loop *gains* (i.e. the EPICs settings) were hard-coded to a value that Brett captured a few months ago:
loading M0_DAMP_L with module #s: 1   2   3   5  10. 
loading M0_DAMP_T with module #s: 1   2   5  10. 
loading M0_DAMP_V with module #s: 1   2   5  10. 
loading M0_DAMP_R with module #s: 1   2   5  10. 
loading M0_DAMP_P with module #s: 1   3   5   6  10.
loading M0_DAMP_Y with module #s: 1   2   3   5   6  10. 
with a gain of -1.17. This is different from the current typical gain of -1.0 (except for pitch which is -3.0), so all DOFs are slightly over damped, except pitch which is under damped.