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.
Time | 0.3µ | 0.5µ | 1.0µ | Sampling Location |
---|---|---|---|---|
12:20 | 10 | 0 | 0 | In cleanroom no work started |
12:34 | 270 | 240 | 290 | In cleanroom - Breaking bolts |
12:39 | 380 | 340 | 110 | In cleanroom - Breaking bolts |
12:43 | 160 | 20 | 20 | In cleanroom - Breaking bolts |
12:45 | 760 | 470 | 390 | By door flange - Purge air escaping from chamber |
12:49 | 210 | 120 | 200 | In cleanroom - Covers on door and flange |
12:59 | 628 | 485 | 185 | In chamber - Cover on |
13:02 | 100 | 20 | 10 | In cleanroom - Cover on, Door outside cleanroom |
13:04 | 860 | 900 | 190 | In chamber - Cover on |
13:15 | 0 | 0 | 0 | In clenaroom - Cover on |
13:17 | 830 | 500 | 150 | In chamber - Cover on |
13:20 | 290 | 300 | 100 | In chamber - Cover on |
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:
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:
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:
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:
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.
|
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= 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).
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.
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.
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.
(And ready for the SUS crew to take over.)
Green QPDs were confirmed to work using green beam on the day we entered the chamber.
Today (June 17), with a help from Gary, IR QPDs were confirmed to work using LED flash light.
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
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.
Under Reliability & Operations, I would also add:
11) Help to Train Operators
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
Richard, Evan
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.
First, let us enumerate some of the mysteries surrounding the EY ESD:
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.
Also, Travis and I are hearing ETMY saturations every so often. The rms drive to EY L2 is 40000 ct or so, which is higher than the 15000 ct that we measured when we first started using EY L2. (Could it just be wind?)
If you, like us, don't like it when your suspensions saturate in full lock, then we suggest trying out a higher L1/L2 crossover. Engage FM9 in H1:SUS-ETMY_L1_LOCK_L, and turn up the gain from 0.16 to 0.31.
Per Jeff's request, here is an excerpt from an email I sent to Evan and Jeff: Some architectures used in amplifiers suffer from a phenomenon known as Phase Reversal wherein the feedback sign of the amplifier can actually change on certain saturation events. I have not looked to see if that is whatsoever possible with the HV ESD amplifiers. Something that bothers me here is that if you are running in low voltage mode, there is no way the high voltage drive signals for the quadrants can make it to the reaction mass. A relay disconnects them. This makes me somewhat puzzled about potential HV/LV interactions causing any sort of actuation force reduction. The actual applied bias could be changing by the time it makes it through the non-trivial series resistance associated with the bias filters (~70kohms), but there would have to be a low impedance on the bias terminal to created the necessary voltage divider. As for the sign flip, I have no answer there. I will check (again) that I didn't do something dumb and make a typo on the + and - wires.
Following up on the notion of phase reversal, I checked all the chips used in the HV ESD Driver signal chain. Here's the result: LT1124 - Input receiver, these are the same architecture as the ubiquitous LT1125 we use everywhere at LIGO, so I'm not too suspicious here. LT1007 - Second stage of input receiver, no mention of immunity to phase reversal in data sheet. This is often a bragging point among chip designers, so I can't eliminate this chip from the list of suspects. OP-97 - Front end chip for the HV output stage, Vcm = +/-13.5V min, this is a possible culprit as the input architecture appears to be jfet based, and it's used in a feedback loop, which is a double whammy for phase reversal. PA-95 - HV driver chip. No mention of phase reversal immunity. Definitely jfet based, used in a feedback loop, and is not grounded on the positive pin. Triple whammy for phase reversal, although it would be hard to exceed the input common mode voltage with +/-430V rails... Mostly pseudo science here, but my two cents.
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.
Jeff, you should also tag
makequad_with_modal_fibers.m (same directory)
This is the function that the generate script calls to add violin modes. It has also changed (a couple of times in the past couple weeks).
Just to clarify, because I don't think I said in any other log, the quadopt_fiber.m parameter file is unchanged in all these updqates. Any custom changes for particular suspensions are meant to be applied to new parameter files now on the SVN:
h1etmy.m, h1etmx.m, h1itmy.m, h1itmx.m, l1etmy.m
, etc.
Currently all these custom quad parameter files are direct copies from quadopt_fiber.m. They are intended to be updated with measurements at some point. h1etmy.m differs only in that the measured violin modes from H1ETMY are included (first 8 modes).
Incidentally, quadopt_fiber.m was created by fitting it to H1ETMY data (as a representative case). Not just M0 to M0 TF data, but the single, double, and triple hang resonances were used too. Also, the measured mass values of the 4 stages are included. Therefore, h1etmy.m may be considered 'complete' in that it is already customized for H1ETMY, simply because quadopt_fiber.m was. The other files are just place holders for the other suspensions currently.
Previously, in log 18809 the violin modes for H1ETMY were hardcoded in the generate scripts. Now that we have customized parameter files, the violin modes have been moved into those.
So, unless you call the generate script with a custom parameter file, you will simply get the modeled modes.
This purpose of these tags is to document the QUAD model that was used in the DARM calibration models circa ER7 (see LHO aLOG 18769). I have *not* yet updated the local copy of the repository to absorb all of Brett's recent work on improving the model (in fact, I really *want* to start using those improvements, which is why I need to make sure the calibration model for ER7 does not depend on the new-ness, and uses these tagged versions). So, yes, eventually, after I svn up the local LHO copy of the quad model directory, I will make new, additional, tagged version of the model, but for now the focus is preserving what we had *before* these upgrades that Brett mentions in his comment. This being said, the ability to add violin modes to the model (albiet with in-accurate frequencies), has been around for a while. As such, I did use the first 25 violin modes modeled with viscous damping in the DARM calibration model. HOWEVER, the above mentioned tagging function did not include the violin modes (i.e. it didn't give generate_QUAD_Model_Production enough inputs) because that script pre-dates the addition of violin modes, and I forgot. So in the same place as described in my above aLOG, I've (1) changed the name of the above mentioned 2015-06-09 tag to reflect that it is with NO violin mode damping (which may still be useful to people): /ligo/svncommon/SusSVN/sus/trunk/Common/SusModelTags/Matlab/ quadmodelproduction-rev7508_ssmake4pv2eMB5f_fiber-rev3601_fiber-rev7392_NOviolinmodes_released-2015-06-09.mat, and (2) tagged a new version of the model WITH violin modes: /ligo/svncommon/SusSVN/sus/trunk/Common/SusModelTags/Matlab/ quadmodelproduction-rev7508_ssmake4pv2eMB5f_fiber-rev3601_fiber-rev7392_WITHviolinmodes_released-2015-06-16.mat Again -- BOTH OF THESE TAGS STILL HAVE INCORRECT LOCAL DAMPING LOOP GAINS, as mentioned above.
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.
Some more information:
As the interferometer gets warmed up, SR3 pitches by 0.7 urad upward while SR2 pitches down by 10 urad via the SRC alignment loop. On the other hand, it is hard to tell how SRM reacts to the heated interferomter. See the attached trend which has the same time period as that Sheila posted.