hugh.radkins@LIGO.ORG - posted 16:46, Friday 06 June 2014 (12253)
WHAM6 ISI Table Masses 3/5 done
Still have 16 10Kg masses to load onto the table both + & - X area.
Still have 16 10Kg masses to load onto the table both + & - X area.
3IFO #3 is being tested now. #4 Optical Table is assembled and will go onto Stage0 Monday. Mitchell Scott & Jim
[Mark B Jeff B Arnaud P]
Yesterday we did some software debugging in the staging building in order to run transfer functions on the assembled quad 08.
When driving the top mass, we usually monitor the lower stages osems, in both osem and euler basis. For some reason the model running for the quad doesn't record those channels (particularly the ones in the euler basis "WIT_{L/P/Y}_DQ"). We decided not to spend too much time understanding what the model situation was, and instead simply not monitor the lower stages channels during the top mass TFs.
The undamped transfer function measurements for the main and the reaction chain are attached.
[Mark Jeff Arnaud]
QUAD08 should be compared to the model called "wireloop" (=wires from UIM to PUM looping around PUM) instead of the "wire" one (=cable segments between UIM and PUM). The first attachment from the alog above was modified since I was using the wrong model for comparison. With the wireloop model there is still a small discrepancy in the second pitch mode (modeled at 1.33Hz and measured at 1.45Hz). By playing with the d values (defined p7 of T080188) I came up with a good match, cf attachment.
Here are the modified d values for reference :
new_dm = old_dm + 0.7mm
new_dn = old_dn + 0.7 mm
new_d4 = old_d4 - 0.8 mm
Also, after an other round of matlab debugging (pb with channel sampling rates in the matlab scripts, path definitions etc...) we were able to get spectra of TOP and UIM osems, with the suspension undamped. Results are attached in the second pdf.
The only thing to notice is the noise content at high frequencies for the left osem of M0 (cyan curve, 1st page). This might be harmonics from the large 60Hz signal.
Jeff B Andres Arnaud
This afternoon we tested the noise seen in the left bosem of the main chain. We swapped left and right osem cables (at the osem output), and measured a spectra before and after. When plugging the right channel to the left osem, the noise was still present in the spectra (cf screenshot) meaning the noise comes from the left osem itself.
Second attachment is a comparison of the transfer functions between different "wireloop" quads. The 2nd pitch mode frequency is varying from quad to quad, but the largest discrepancy is on QUAD08.
[Andres Arnaud]
Today we replaced the left osem of the main chain of QUAD08 in the staging building with an other BOSEM (stolen from one of the 3rd IFO TMS). New OLV were stored, offsets and gains were set in medm.
Results of individual osems spectra are attached. The M0 LF channel dosen't show the elevated noise seen yesterday anymore
(Travis, Betsy, Margot)
This morning, we rearranged the new ITMx (ITM03) monolithic lower structure sections and the now "old" ITMx sections and restowed them for the weekend in the storage container. We pulled the FC from the CP-front and the ITMx-AR prior to putting the main and reaction chains together. As planned, this involved swapping out the UIM on the reaction chain such that it matches the UIM on the new main chain. For the record, we are reusing all OSEMs from the "old" ITMx on the new monolithic one, so testing will be straight forward.
We will be ready to hoist the reassembled monolithic lower structure assembly onto the arm and reinstall it in-chamber on Monday.
We also paused to catch a moth that we observed fly into the cleanroom mid-morning.
Meeting Minutes:
model restarts logged for Thu 05/Jun/2014
2014_06_05 12:55 h1isietmx
2014_06_05 13:26 h1isietmy
2014_06_05 14:12 h1iopsush56
2014_06_05 14:12 h1susomc
2014_06_05 14:12 h1sussr3
2014_06_05 14:12 h1sussrm
2014_06_05 14:18 h1isiitmy
2014_06_05 14:39 h1isibs
2014_06_05 14:42 h1susbs
2014_06_05 14:53 h1isibs
2014_06_05 15:00 h1isiitmx
2014_06_05 15:42 h1isiham2
2014_06_05 15:52 h1isiham3
2014_06_05 15:56 h1isiham4
2014_06_05 15:58 h1isiham5
2014_06_05 16:00 h1isiham6
2014_06_05 16:08 h1broadcast0
2014_06_05 16:08 h1dc0
2014_06_05 16:08 h1fw0
2014_06_05 16:08 h1fw1
2014_06_05 16:08 h1nds0
2014_06_05 16:08 h1nds1
2014_06_05 16:09 h1nds1
ISI model work, timing error on sush56, daq restart to support ISI.
All optics except two steering mirrors (one behind OM1 and one close to OM1) were fixed down to the nominal position. We need to move these two steering mirrors tomorrow.
Two V beam dumps are to be installed tomorrow.
OMC was freed, OMCS BOSEMs were centered.
OM1 was freed, OM1 BOSEMs were centered.
OM2 and OM3 are going to be freed and BOSEM centered tomorrow. Damping magnet gap for all Tiptilts are to be set tomorrow.
All 5 QPDs, WFS(DC) and OMCDCPD will be tested tomorrow.
Detailed alog will follow.
Details: WFS path was made different from documents (documents are wrong), small difference from LLO.
Have found that all HAM6 layout drawings are wrong about WFS position. The distance from the lens on the sled to WFSA should be 191mm and WFSB 475mm (T1000247), but layout on documents like D1000342 both of them are about 3.5 to 4 inches too short. This is not a problem for WFSA because there is a room to move it, but moving WFSB back to gain extra 3.5 to 4 inches would make WFSB base interfere with one of the balast masses on ISI.
LLO originally changed the sled layout (see alog 2888), Corey didn't know about it when he made the sled (Corey's alog 12083), but anyway we thought that this was how LLO did it, and making this change would require swapping both of the mirror mounts (from left handed to right handed) which sounded like a hassle, so we decided to move the steering mirror M102 for WFSB as well as WFSB itself about 3inches downstream to the west. Later I found that LLO installation look more like D1000342 (see the picture of alog 8224), it's hard to see how it was exactly done but I'm asking Chris and Valera.
Some measurements:
There's some uncertainty in where exactly the diode face sits, and the accuracy of the above is probably something like +-2mm.
Details: AS_C QPD (not sled) had a smudge and was swapped
Fresh out of the bag, there was a smudge on the AS port QPD window in D1101654 S1202409 QPD/cable assy, and it was very close to the center. We didn't have to use any special light to see that it's there, but we needed to look at it from a certain angle.
I attempted to clean it on the spot using a wipe and alcohol, but it didn't go away, maybe it's some kind of scratch or abrasion. It's probably fine for some other purposes but I didn't want to put it in the AS path.
We pulled the QPD out of the assy and dropped the spare QPD in.
For future rerefence:
Bad IR QPD: #8. This is stored in a bag, not in the spare QPD cage.
Replacement IR QPD: #18
We have now only one spare IR QPD in the spare QPD cage, which is #15.
But we still have one spare IR QPD cable assy pre-assembled with two QPDs.
Other details:
Confirmed that serial # of OM1 TT stage is 002, OM2 004, OM3 033, as per Rich's alog 8612.
I didn't like the way OMC REFL beam diverter (BDV1) was assembled, as the peek washers face upstream. There's some (admittedly small) possibility that they are burnt when three things happen at the same time, i.e. IFO loses lock, TT or OMC is shaken, and the fast shutter is non-existent or malfunctioning. Flipped things such that these washers are downstream of the black glass piece, but Corey found that with this new configuration the beam diverter will interfere with balast masses. So, unhappily I flipped everything back.
At LLO two dedicated beam dumps for beam diverters were installed (Chris's alog 7573), we need to copy it.
IN-VACUUM DCQPD LOCATION MAP E1101174-v13 updated accordingly.
J. Kissel, D. Barker Following the instructions in SEI aLOG 491, I've svn up'd the following common isi corners of the userapps repo, ${userapps}/release/isi/common/models/ ${userapps}/release/isi/common/src/ ${userapps}/release/isi/common/medm/ to receive software updates from ECR E1400239, and integration issue 901. I've then recompiled, reinstalled, restarted, and restored the following models (in chronological order): h1isietmx h1isietmy h1isiitmy h1isibs h1isiitmx h1isiham2 h1isiham3 h1isiham4 h1isiham5 h1isiham6 Only the ETM chambers are still fully functional, but for each chamber (because most corner station guardians were still requesting fully isolated), I requested the guardian to go to OFFLINE before the four R's. Once 4R'd, for the BSCs, - Confirmed that the T240MON responds as expected, showing red if T240 values are above the HI THRESHOLD, and not returning green until spending DELAY number of seconds below LOW THRESHOLD - Confirmed that the T240MON values were restored to HI 20000, LOW 5000, DELAY 120, if necessary. Apparently these new-ish channel's values were never captured in the ETM chamber's safe.snaps. - For ETMs only, to confirm software changes were successful, I - used guardian to being chambers back up to FULLY_ISOLATED, to confirm the safe.snap didn't lose anything else vital. This was successful. - used guardian to transition to DAMPED, such that isolation loops were turned OFF. Set stage 1 (ST1) watchdog (WD) T240 threshold to a value that would normally trigger the WD; I chose 0. This DID NOT trip the watchdog as expected with the new software changes. In addition, the saturation counter that appears in the "FIRSTTRIG" column above the label for T240 limit begins counting up. This was successful. - with the T240 threshold still low, used the guardian to request FULLY_ISOLATED. After a short period of time (the time it takes guardian to set things up for turning the isolation loops), the watchdog tripped, as soon as the isolation loops began to be turned on, as expected. This was successful. - RESET the ST1 T240 WD threshold to its nominal value of 32760, RESET the WD, and guardian happily marched all the way back up to FULLY_ISOLATED, resetting the T240 saturation counter along the way. This was successful. All other changes appear successful -- the T240 matrices have expanded, a Z to RZ filter bank now exists. and a new isolation filter gain comparison exists whose output presumably feeds to the ODC vector. The following still needs doing: (1) Update safe.snaps to include the correct threshold values for the T240MON (2) Update safe.snaps to include the correct ISO gain comparison values (3) Test Z-RZ path for functionality / usefulness (4) Add matrix elements for new T2402CART matrix elements (5) Update safe.snaps to include the new T2402CART matrix elements Rich will work on (3) and (4). But I don't know in what state the ISIs need to be to capture a new safe.snap, so I'll leave (1), (2), and (5) to those who pay closer attention to the ISIs. The corner station BSC-ISIs and all HAM-ISIs remain OFF in some way or another (user watchdog, masterswitch, or IOP DACKILL) for the vent, with their Guardians set to OFFLINE and paused. The restarted the "DAQ"/data concentrator/h1dc0/frame builder to account for the new epics channels and filter models at 23:07 UTC. I also accidentally compiled, installed, and restarted the h1susbs because my fingers have too much muscle memory and I mistyped h1isibs. No good reason otherwise!
DAQ restart to sync up with latest ISI models.
- Greg going in to BSC3
- Andres and Jeff to output arm
- Fil to EE room to test AA and AI chassis, turning off electronics for BSC 1,2,3
- Mitch to the west bay with Scotty
- Jeff K restarting ISI models
- Justin going to EY to transition to laser safe
- Peter King to H1 enclosure first and then H2 Enclosure afterwards.
Betsy, Travis, Danny, Margot
Today, we finished deinstalling the ITMx lower section of the QUAD using the install arm and elevator. All went as it was supposed to. After transfering the load to the manlift and attaching the LSAT structure for support, we set it down onto one of the LSAT trollies we have. We then separated the Main and Reaction chains. Margot and Danny FirstContacted the CP front and back surfaces (spray for back, paint brush for front due to bump stop locations).
While FC work was going, Travis and I went into BSC1 and started prepping the ITMy for deinstallation. By the end of the day (and some final muscle from Danny) we had the masses locked in positions which facilitate upper and lower segment separation, the cross braces and sleeve structures removed. (Of course, see yesterdays alog for exact details of how this really happens with floor panels removed, etc.) We also finished pulling the balance of the witness plates and witness optics in BSC1 and BSC2.
Note, when we removed the flooring in both BSC3 and BSC1 we found hidden treasures. To be continued...
:)
BSC 3 goodies found under flooring:
BSC 3 goodies found under flooring:
Arnaud, Dave
we rebooted h1sush56 after it developed large IRIGB offsets. We cannot find any reason for the problem, doesn't seem to be linked to other model changes or work in CER. No activity in MSR at the time.
Procedure was: stop user models, stop iop model, take node out of Dolphin fabric, powerdown from console, power up by pressing front panel switch.
A revised version of the document T1400384-v2 has been posted on the DCC and appended here. The changes are: 1) a calibration error in the data from the accelerometers has been corrected 2) a calculation estimating the equivalent displacement noise from the baffle scattering and comparing it with the sensitivity of advanced LIGO is included. The results have not changed. The new insulation does not suppress the acoustically driven noise as well as the old insulation and the estimated scattering noise does not leave enough margin to be certain that it will not compromise the interferometer performance.
John Worden, R. Weiss Vibration measurements of the beamtube with the new R10 insulation and aluminum jacket were made and described in the appended document. The new insulation reduces the acoustic coupling to the beamtube but not as well as the initial insulation. The data enables a more detailed estimate of the phase noise from the beamtube motion due to the faulty HR coatings of the new test mass mirrors. The DCC number of the document is T1400384.
Error in the document. Please see T1400384-v2 or LHO log entry 12232
stage 1 actuators, this happened when diff lost lock.
The same thing happened again, this time the plotting script worked.
ETMY sus also tripped just now
Since Sebastian and Lisa have been trying to look into this, Rich and I had a look at some trends from around the time of these trips.
The ALS DIFF guardian down state exits too soon, moving on to the prepare state too soon (alternatively, it fails to clear the history of DARM, which is par tof the down state but isn't working.) This causes a transient to be sent to the suspension. Of course we need to fix the guardian, but also need to decide if these kind of transients should be tripping the ISIs.
The screen shots below show the input to the suspension from the LSC model, the outputs to the test mass and to the top mass, and the time of the WD trip for two of these trips.
Thank you for the follow up Sheila.
I'm still analyzing those trips to be sure that we have a full understanding of what's happening before taking any decision. I should have a full report before the end of the week.
