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.

= Mid-day Summary =

7:45 Christina and Karen to EX and EY to check garb in clean rooms.

8:35 Corey, Keita, Kiwamu to EX (TMS work)

8:28 Jason and Peter to PSL

8:41 Richard with the electrician in LVEA

8:44 Karen and Christina leaving EX, heading to EY.

       Andreas and Jeff B to EY to get supplies, then

8:59 Fil to EX - CHeck tools for ESD retrofit

9:02 Richard back

       Hugh to Ebay - reset B seis STS2.

9:17 Hugh back

9:30 HAM6 clean room fan on

9:54 Let the water system guy in

10:02 Sheila restarting OAF model

10:10 Karen and Christina out of EY

10:18 Gerardo to EY

10:22 Greg to LVEA (store parts)

10:26 Betsy at EY, with whole bunch of other people. Expect EY tripped. Don't do anything, Betsy will take care of it.

10:35 Jeff B and Andreas back

11:00 Andreas to HAM2 (drop off stuff)

         Karen vacuums mechanical room

11:40 Gerardo back from EY

11:59 Corey et al. out of EX

          EX now laser safe

12:00 TJ takes over. Go team!

Corey, Keita, Kiwamu,

We conituned working on the remaining tasks for the TMSX in chamber (see alog 19157 from yesterday).

[Strain Relief for QPDs]

This morning we installed the strain reliefs for the two QPDs in which we had a difficulty inserting a screw due to bad threading. Today, we brought 10-32 screws so that the screw can go all the way through to the back without any interference from the bad threads. We put combination of a nut and washer on the other side to hold the 10-32 screw and the strain relief parts. We did this on the two QPDs. So now all four QPDs have the strain reflef parts installed.

[Balancing of the table]

We then balanced the table such that the green light is retro-reflected off of ETMY. The table seemed to have pitched by some amount. We decided to move the counter mass at the bottom of the table. The adjustement went very smooth and we were able to get the beam retrao-reflected all the way back to the PD on the ISCTEX table. Touching the TMS digital bias suggested that the pitch angle is good with a precision of about 4 urad. While pitch is good, yaw seemed to be slightly off. So we moved the digital bias in yaw as well and confirmed that adding an additional +40 urad (resulting in a bias of ) in the digital bias can give us a decent alignment on the reflection PD. So we are good in yaw too.

[Addendum]

After initial balancing we were concerned that we did not use vented washers for the two QPDs which required the screw/nut workaround.  Keita found that one QPD did NOT have a vented washer, so a vented washer was installed.  This required a re-balance.  We were a little off in pitch, so a counterweight (1/4-20 screw) was added to pitch the TMS.

Photos of this work from Mon afternoon & Tues morning is on ResourceSpace here.

EX is now Laser Safe.

(And ready for the SUS crew to take over.)

J. Kissel, A. Pele,

Over the next few days, we intend to make changes to the QUAD models and the BSC-ISI models. These changes are covered in the following ECRs:

    SEI: (Work Permit: 5284)
      - Official integration of MICH Freeze infrastructure for the BSC ISI's library part.
        ECR: E1500253, 
        Int. Issue: 1063
      - Move / rename the GND STS BLRMS channels out of ST1 BSCs and up to the top-level ISI-GND block
        ECR: E1500245, 
        Int. Issue: 1059.
      - Adding Tidal correction inputs to the BSC-ISI:
        ECR: E1500270, 
        Int. Issue: 1067

    SUS: (Work Permit: 5285
      - Accomodate both observatories' versions of tidal control feedback to the QUADs:
        ECR: E1500228, 
        II: 1055
      - Reconcile LLO's QUAD top mass bounce and roll mode damping to use DARM_CTRL and any AS WFSs instead of DARM_ERR.
        ECR: E1500090, 
        II: 953
      - Modifications to the QUAD model for violin mode damping:
        ECR: E1500271,
        Int. Issue: 1067

And the following non-version controlled software will also be changed:
      - Update the corner-station LSC model to accomodate the above MICH freeze infrastructure 
        (an update to the ${userapps}/lsc/common/models/lsc.mdl, and plus new connections to IPC at the top level). 
        Work Permit: 5284
      - Update the OAF model to modify QUAD bounce and roll mode damping monitors 
        (an update to ${userapps}/isc/h1/models/h1oaf.mdl)
        Work Permit: 5278
      - Update to top-level CAL-CS model to add the blind injection channels to the frames. 
        (an update to ${userapps}/cal/h1/models/h1calcs.mdl)
        Work Permit: 5286
      - Update to the ASC model to allow for flexible choice of error signal for bounce and roll mode damping, 
        i.e. adding the WFS AS_A and AS_B YAW DOFs as possible choices 
       (an update to ${userapps}/asc/common/models/ASC_MASTER.mdl)
        Work Permit: 5278

List of commissioning tasks

The list below is for the time between now and O1. Since the sensitivity has reached the nominal goal set for O1, we plan to prioritize reliability and operations issues to maximize the up-time.

Reliability and Operations

1. MICH freeze/feed forward
2. Move to 90mHz blends everywhere
   Beam splitter and in transverse direction on test masses.
3. Better automation of bounce/roll damping based on monitors
4. Investigate alignment drift of SR3 (heating)
5. Alignment stability at high power
6. Thermal tuning of ITMs (stability, check contrast defect, sensitivity, ASC matrix)
7. Make a permanent PI monitors (down-convert 15kHz and record)
8. Optimize PI mitigation
9. Duty cycle improvements in locking procedure
10. Damp violin mode harmonics (needs more filters in SUS model)

Sensitivity

11. Monitor discharging, charge noise and ring heater coupling
12. Angle to length decoupling; try to make it permanent.
13. Intensity noise coupling and mitigation
    Are the IMC ASC offsets stable without auto-centering?
    Minimize acoustic noise coupling (new PSL periscope mount ready?)
14. Move to in-vac refl sensor (or figure out why we can't)
15. Frequency noise investigation; why is it so high?
16. Oscillator noise couplings
17. New OCXO and EOM drivers
18. Re-engage low pass on ETMY ESD
19. Investigate/find low frequency noise
20. Investigate beam tube dust glitches (histogram, distribution, quiescent rate)
21. HAM6 scattering measurements after the shroud installation and beam diverter move
22. SRC/PRC alignment effect on sensitivity
23. Check noise on all coil outputs(?)
24. Check/explain shot noise number (null stream)
25. Find best beam spots on ETM/ITMs (maybe wait for ER8)

Others

26. Finish SRC length/Gouy phase measurements
27. Final OMC alignment scheme
28. OMC alignment scheme that doesn't rely on the OMC SUS
29. HWS to investigate thermal loading
30. Timing studies

Kyle, Gerardo 

Vented X-end (DP < -45 C)-> Vented Y-end (DP < -35 C) -> Installed NEG assembly on BSC6 -> Installed TMDS reducing nipple+valve+elbow on BSC10 


Kyle, Gerardo, Bubba 

Removed BSC9 West door at X-end -> Removed BSC10 North door at Y-end 


Bubba 

Connected TMDS 100 psi line to purge-air skid

(Keita, Kiwamu, Corey)

After the Vacuum crew removed the door, and Jim Warner locked up the ISI (& removed the Contamination Control plates), we started TMS work.  Summaries of the TMS activities are below:

1) Green Clipping

The ETMx Bias were: 

• Pit = 442.0 urad
• Yaw = 82.6 urad

In order to center the beam on the ISCT-EX REFL_PD, the ETMx was steered to the following biases:

• Pit = 413.3 urad
• Yaw = 74.6 urad

After this Keita entered the chamber and looked for clipping.  He started with the first steering mirror on the TMS, the one that showed very bright scattering back in Feb.,  and no clipping was observed this time though the beam was somewhat low, and there was some ghost beam hitting the top right edge.

Keita checked downstream optics and no clipping was observed either. No changes were made to the TMS optics alignment.

2) Strain Relief of QPDs

Ran into a problem with attaching the Strain Relief Parts (D1101911 & D1002110) to the QPDs.  The problem was attaching the Strain Relief Clamp (D1101911) to the main QPD Housing.  Unfortunately, the 1/4-20 hole in the housing had bad threads for two of the four QPDs.  It's a thru-hole and screw could only go in a thread or two.  My guess is the machinist tapped the holes from the backside with a tapered tap & didn't tap all the way through.  So some of the threads at the entrance of the hole aren't cut completely. 

Keita & Kiwamu went ahead and installed the Strain Relief Assy on the two QPDs which were fine.

As for the remaining two, we might use thinner 10-32 or 10-24 screws, long enough to go through the QPD base and the strain relief combined, and use a nut and two washers if such things are found. Otherwise we'll leave them without strain relief, as there's more than 1/4" of space between the cable collar and the metal part of the QPD support structure.

3) Krytox Beam Diverter

Corey went into the chamber, loosened the screw that attaches the shaft collar to the axle, slid the axle and the jewel bearing out on one side, applied Krytox, did the same to the other side, rebalanced the diverter by attaching 5 1/4" and one #8 vented washers as a counter mass, and assembled everything together.

This was done all in situ. Tested opening/closing via MEDM several times and it worked fine.

I modified ASC_MASTER today to give us the option of using AS 45 Q Yaw signals to damp roll, because yesterday we saw that this was needed for ETMX.  The model is committed, and I added an medm screen that is linked from the ASC overview and the small bounce roll monitor screen for the matrix.  The ASC model changes were done today because Adam at LLO will also work on this library part tomorow durring maintence.  

I also added log scale monitors to the oaf model, but made two typos in doing this.  I've fixed the mistakes and recompiled the model, we will wait to do a make install until the normal maintence time tomorow.

To correct problems with the Simulink web view of models (accessible from https://lhocds.ligo-wa.caltech.edu/simulink/) several models have been changed to be saved at the top level of the model.  If this isn't done, the top level of the model is not generated for the web view.  The models which were changed are:

h1iscex
h1iscey
h1isietmx
h1pemcs
h1pemex
h1pemey
h1pemmx
h1pemmy
h1susauxb123
h1susauxh34
h1susetmx
h1susim

There are still a few models that need to be changed.  

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.

It seems that the pitch control signal sent to SR2 (from the AS_C sensor) is correcting mostly for motion of SR3, especially in the first hour after powering up. We should think about changing this feedback from SR2 to SR3 after the engineering run.