travis.sadecki@LIGO.ORG - posted 10:31, Tuesday 22 July 2014 (12913)
ETMx PCal target removed
(Sheila Daniel)
Finshed the installation and alignment of the ALS WFS auto-centering for EY. All 4 dofs were engaged. TFs TBD. The first channel of the MCL controller for WFS A seems to have a bipolar input range, whereas all others are unipolar. This is reflected in the applied output offsets of the servo.
no restarts reported
(lots and lots of people)....and I want to thank ALL these people for all their help today. Everybody was willing to pitch in and help, and was fantastic that that happened.
Its been another long day and I am tired so this will be quick (more detailed report to come)....also apoogies if this alog makes no sense. My mind is mush now.
HAM5 was closed up today. ISI balance was rechecked and slightly altered, clean of chamber happened, had also to pause for some time where we had to wait until particle counts dropped to level happy to peel FC off SR3 but eventually got both doors on. We did notice that when FC pulled immediately it looked awesome, and then in the time before door went on, started to see small amounts of particulate already coming back. After doing some quick TFs in a couple DOF's it was given the okay to put doors on and they were put on as quickly as we could. We did learn various things on how to speed up, etc.
Rough timeline: 1st contant removed 11.20am 1" optic. 11.44am first contact removed from SR3 optic. North door on ~12.37pm, South door on ~13.14pm.
Changed up the order for HAM4 door and ISI was half unlocked and North door went on before started anything (discovered after door went on that first contact is still on the inside of the viewports :-(...after discussion with Mike L we will pull off the viewports at a later date to remove). From that we had to wait an awful long time trying to wait for particle counts to drop out of the hundreds. Things learned is we found counts spike when door gets put on, couldnt have the BSC chamber cross flow on as would make counts in the hundreds in HAM4, same with people trying to work in BC1, or even lifting a cover elsewhere. Eventually counts went down and we pulled FC on SR2. Unfortunately right at the end of the pull the gas bottle ran dry on the top gun :-( :-(. And immediately looking at the SR2 optic it looked bad...as if we had never used FC. After a bit of back and forth and a round table discussion it was decided we would try to first contact again with everything its its present state. That is to try to re-spray FC using the hold on cone and if that didnt work to paint on FC after first trying blow off anything that we could. We found the cone didnt work (wouldnt fit) and so we painted. Was a pain as coulndt really see it, but we got it done in the end (well done Kate and Rich for staying behind with me to get this done..your help is appreciated more than can express). So will try to pull FC again in the morning and we will see what we see.
Hopefully others will make alogs regarding particle counts, etc. ...and I may try to write a more detaield report at a later date with some photos etc depending on if they turned out when look at.
Measurements complete and data committed to the sus svn. Unfortunately there still are indications of rubbing affecting the first vertical peak.
Stuart A. Jeff K. Arnaud P.
Today, after HAM5 chamber closeout, we took tfs measurements on all degrees of freedom of SR3 and SRM, using dtt. The suspensions were NOT damped during the measurement. SRM looks healthy (cf first pdf, compared with last tf taken in may), but unfortunately we think SR3 is rubbing, looking at the V2V transfer function (3rd page of 2nd attachment, black curve). The first vertical mode at 1.07Hz is unexpectedly damped, and does not look similar as the previous tf taken on July 15th, after the magnet repair. We tried to run the same vertical tf applying offsets in different directions hoping to find a configuration were the resonance would come back to a high Q, but without any luck (cf screenshot). We will run long tfs overnight using matlab to make sure it's not some kind of measurement artefact (which we doubt), and see how it looks tomorrow.
We also noted SR3 M3 osem alignment UL is not ideal (cf 2nd screenshot), which might have been exacerbated by this morning's HAM5 ISI rebalancing.
Measurements were added to the sus svn :
-----------SRM-----------
Data/2014_07_21_1400_H1SUSSRM_M1_WhiteNoise_L_0p01to50Hz.xml
Data/2014_07_21_1400_H1SUSSRM_M1_WhiteNoise_P_0p01to50Hz.xml
Data/2014_07_21_1400_H1SUSSRM_M1_WhiteNoise_R_0p01to50Hz.xml
Data/2014_07_21_1400_H1SUSSRM_M1_WhiteNoise_T_0p01to50Hz.xml
Data/2014_07_21_1400_H1SUSSRM_M1_WhiteNoise_V_0p01to50Hz.xml
Data/2014_07_21_1400_H1SUSSRM_M1_WhiteNoise_Y_0p01to50Hz.xml
----------SR3------------
Data/2014_07_21_1400_H1SUSSR3_WhiteNoise_L_0p1to50Hz.xml
Data/2014_07_21_1400_H1SUSSR3_WhiteNoise_P_0p1to50Hz.xml
Data/2014_07_21_1400_H1SUSSR3_WhiteNoise_R_0p1to50Hz.xml
Data/2014_07_21_1400_H1SUSSR3_WhiteNoise_T_0p1to50Hz.xml
Data/2014_07_21_1400_H1SUSSR3_WhiteNoise_V_0p1to50Hz.xml
Data/2014_07_21_1400_H1SUSSR3_WhiteNoise_Y_0p1to50Hz.xml
Phase 3a DTT TF measurements continued for the lower stages of SRM as follows:- - SRM M2-M2 undamped results comparison (see allhstss_2014-07-21_Phase3a_H1SRM_M2_Doff_ALL_ZOOMED_TFs.pdf below) - SRM M3-M3 undamped results comparison (see allhstss_2014-07-21_Phase3a_H1SRM_M3_Doff_ALL_ZOOMED_TFs.pdf below) ISI Status: ISI unlocked, not damped, no isolation for the duration of these measurements. SRM alignment: Zero pitch and yaw offset. Summary: SRM L DOF TFs for both stages appear a little ratty, but this is most likely due to turbulent purge air flow in chamber. However, both lower stage TFs appear consistent with other H1 HSTSs and the model, therefore raising no concerns. All data, scripts and plots have been committed to the sus svn as of this entry.
Dont tell me SR3 is rubbing. Thats enough to crush my spirit today............I could of sworn I checked all EQ stops. And I dont remember altering any vertical ones on SR3...excpet ones below the IM mass and they are still a logn way away. *sigh*. My fingers are crossed for measurement artifact.
Mike V, Rick S, Darkhan T
This afternoon the alignment of the ETMX PCal IR path was finalized. The upper/inner beam did not require adjustment of the periscope optics. The outer/lower path required realignment of two mirrors.
The alignment of the camera optics was finalized. The paths from both camera viewports were adjusted. The camera and enclosure that were installed in the upper viewport on the West side of the beamtube has been removed for this work, and will be re-installed at its final position in the lower viewport on the east side, next to the OpLev transmitter.
Particle counts were taken before, during, and after the in-chamber work. After entering the chamber, Rick wiped the floor plates to reduce stirring up dust. The actual counts will be posted as a comment, but the cleaning reduced the after-chamber-work particle counts from ~2000 cts to ~350cts for 0.3 micron/c.f.. A great improvement.
08:55 Daniel and Sheila working on optics table at end Y ? 09:00 Jodi reports H1 PSL chiller is alarming 09:02 Hugh to HAM 3,4,5 to balance check seismic 09:05 Jeff B. and Andres going to HAM 4 and 5 for contamination control closeout work 09:09 Paul and Jordan to end Y to work on PEM 09:10 Jeremy B. and Matt H. going to HAM 4 and 5 for closeout work 09:12 Jeff B. added 200 mL of water to the H1 PSL chiller 09:12 Nathan starting unattended work in optics lab with laser on 09:16 Mike V. to end X, PCAL work? 09:23 Rick called from end X, looking for Mike V. 09:30 Doug C. to ITMY, spool area to calibrate survey equipment 09:37 Jason heading out for ITMY alignment 09:46 Aaron to end Y to install illuminator chassis in SUS rack 09:52 end X is in laser hazard 09:53 Travis to ITMY to work on reaction chain alignment 11:15 Stewart and Arnaud to HAM 4 and 5 to better communicate with closeout team on transfer functions 12:48 end X is laser safe 12:59 Aaron to end Y with power cord for illuminator chassis, and then to end X to install illuminator chassis there ~13:30 Dale leading tour in control room 14:00 start of putting doors on HAM 4 14:11 Jeff K. to end X to measure cable tray lengths 14:12 Stewart into LVEA to start work on SR2 14:46 Hugh to electronics room to check coil driver chassis 14:56 Mike L. going to HAM 4 to talk to closeout team 15:05 Jeff K. back from end X 16:01 Nathan done unattended work in optics lab 16:30 Fred taking 2 visitors on tour through the LVEA 16:30 standing down on putting door back on HAM 4, reapplying first contact
Mike V, Rick S, Darkhan T
This morning Rick and Mike went into chamber to continue with the alignment of the PCal transmitter and periscope, with Darkhan outside. Alignment now looks good.
This afternoon we will continue with alignment checks of the camera mirrors.
Particle counts were reasonable before work commenced (attached photo IMG_0086), however after exiting chamber counts were very high (attached photo IMG_0087).
This is most likely due to stirring up dust; we will wipe the floors as well as the PCal periscope and Manifold Cryo Baffle which are noticeably dirty.
Some odd noises were also coming from the clean air compressor (very low audible tone), Kyle is investigating.
High Potential (HIPOT) testing essentially applies a predetermined high voltage to a device under test. If a threshold current is detected, the tester shuts down and issues an audible and visual alarm alerting the operator. The following items associated with the HAM6 ISC Fast Shutter system have been HIPOT tested using the indicated DC voltage. The threshold current was set at 300uA for all measurements. (Refer to D1400225 for cable components and D1400078 for overall shutter details) 1. Air-side 35 foot, 6 conductor cable - Tested at 3kV in every possible wire permutation including the connector body 2. 6 Pin vacuum feedthrough (Military 5015 connector compatible feedthrough) - Tested to 1.5kV 3. In-vacuum 10 foot, wiring harness (from flange to shutter) - Tested to 1.5kV while attached to vacuum flange 4. Fast Shutter Coil - Tested to 1kV as a fully assembled unit (between coil and fast shutter body) The chosen voltages are somewhat arbitrary based on an internal dialog with myself, but the maximum system voltage for the fast shutter is 500VDC. The fast shutter operational peak current is just under 30 amperes with that peak lasting a few milliseconds.
While working around the ISC rack behind HAM6, we noticed a cable labelled ISC_410 falling off. Not sure if it was plugged or not before. tbd
We are still installing equipment in this rack and pulling cables.
Based on yesterdays FC troubles I went back and had a look at some of my alogs regarding humidity in chamber.
By looking at the various pics I posted of particle counts in links:
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=12874
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=12873
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=12866
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=12859
You can see the humidity in chambers varies from 13%-33%. I was surprised at this, and I have to take back what I had said to Kate and Calum yesterday at how I said I had noticed that the humidity levels usually stayed pretty constant in chamber here at LHO
No surprise,
According to the weather station at PASCO airport (KPSC) the relative humidity on Sunday ranged from 71% at 5am to 21% at 6pm.
The indoor humidity is influenced by the outdoor humidity and temperature.
Inside a chamber the air near a door is a mixture of purge air and LVEA air. The purge air is nominally 0% RH but the LVEA has been ranging between 20 and 40 recently. In addition those water molecules are moving way faster than the purge air and are very happy to move upstream.
Summary of the problem:
We have been struggling for several months with what we believe are direct (magnetic) couplings between the BSC-ISI actuators and seismometers . We have tried to measure and subtract the main coupling (Z to RZ). We have obtained substantial improvement in the T240 response, but no improvement in the optics low frequency motion as seen by the optical levers. Our conclusion at his point are, that we need to identify and subtract the couplings in other directions and/or there is noise injection somewhere between Stage 1 and the bottom mass of the quad.
Low frequency couplings analysis:
The two BSC-ISI units locked at LHO (ITMX, ITMY) give us a great opportunity to study the low frequency direct coupling from the actuators to the sensors. This document compares transfer functions of the BSC-ISI when the two stages are floating (unlocked/free) and when the two stages are locked. We use two series of measurements performed on ITMY. The goal is to figure out whether the low frequency features in the inertial sensors response are due to motion (translation or tilt coupling) or due to direct pickup (magnetic fields).
Comments are embedded in the document.
The last slide carries the most important information.
Following up on this open issue, here is a comparison of ITMX and ITMY. Both units were locked during these measurements to identify direct couplings. The first page shows the CPS transfer functions, from the V1 actuators to all local CPS. We can see some differences between ITMX and ITMY cross couplings. The second page shows the T240 response. The results of the two units are very similar.
Following up on Matt's alog above and to expand on a few items.
Before we agreed to "try again" with FC at SR2 in HAM4 we had a round table with Calum, Matt, Jeff, Rich, Kate and Mike Landry. Based on the gas and the issue of higher counts in chamber we decided to try again. (We could left and dumped to bug list but we thought worth to try again.) As Matt mentions we discussed several options including re-doing it with bolt on cone, using handheld cone or brushing. To use bolt-on cone we would needed to have locked ISI, removed suspension stops etc ... and would have lost ~ 1 days work. So we gave team option of handheld cone or brushing. We went through details associated with brushing i.e. 1) clean with gas from top gun first prior to brushing 2) use new and many brushes 3) only brush if guys happy with visible inspection with green light prior to brushing 4) use new batch of FC which just arrived st LHO on 21st July 2014.
I should also add that regardless of what happens today they will move ahead with close i.e. if successful we will move on and if still "dirty" we will take photos then write up a bug report and move on.
Two recommendations from this (while not responsible for issue they are good lessons): -
1) During pulling etc ... one person should be on gas bottle / top gun duty and watching bottle pressure. I was doing this while present but didn't do a great job re-assigning it i.e. I asked Matt to re-assign rather than doing it myself. (Betsy had got 2x bottles re-filled as well so they were available.)
2) Colored or different bottles for 1:1 mix versus cleaning mix or other. Why? Later (at 4am) I remembered that Kate and I had observed that the FC spray on SR2 looked different and that particle count had been low. I wonder if I grabbed the wrong bottle from the table and perhaps sprayed with a mixture that had more thinner than polymer? This has since turned out not to be the case as was reminded we pump before use to check consistency. (Should also mention we do label bottles with mix date, mixer and exp date.) Still worth a look though on colored or different bottles.
PLEASE LOOK OUT FOR FULL ALOG ON THIS FROM KATE.
Celebrating SR2 being repainted and what an epic work week its been