Jamie, Fabrice,
I am posting for the records and for discussion the WD trips we observe while tuning the turn on procedure for the guardian.
no restarts reported.
The results are given in the attached pdf file. The atmospheric leak rate is less than 5.5 +-0.6 x 10^-9 torr liters/sec. The hydrogen outgassing rate referred to 23C is 6.0 x 10^-14 torr liters/sec/cm^2 close to the value measured in 2000.
Last night, undamped transfer functions of H1 TMSY were ran (Phase 3a) with the ISI damped. 3 different drive amplitudes were tried to see if cables are not adding non linear effects.
In orange excitation amplitude is 10000, in black drive is 150000, in pink drive is 20000. TF is consistent throughout the drives.
Differences in frequency of resonnances can be seen in the L V R P degrees of freedom:
First roll mode at 0.68Hz splits in three modes 0.68Hz 0.72Hz and 0.79Hz
First Pitch mode at 0.74Hz splits in two modes at 0.72Hz and 0.79Hz
First Vertical mode at 0.69Hz splits in three modes at 0.67Hz 0.72Hz and 0.79Hz
Second Long mode at 0.74Hz (pitch coupling = first pitch mode) splits in two modes at 0.72Hz and 0.79Hz
All differences can certainly be explained by the change of cable routing when moving cartridge from BSC6 to BSC10. (For details on how the current routing looks like see pictures on alog 11021). Since the actuation is working properly, and the suspension still provides passive isolation above the resonnances, it seemed acceptable to move on with installation.
This morning, SEI, TMS, and SUS gave a cursory "approval" of their systems in order to proceed with chamber close-out tasks. So, after lunch, Margot and I applied First Contact to the ETMy-HR surface which will be pulled just before closing the door tomorrow. The order of events this afternoon (and late morning in order to catch the alog up):
Jim locked the ISI and put final touches on chamber feedthru cable routing.
Apollo+Joe+Gerardo had a viewport party at the BSC10/6 area.
Margot and I locked the lowest masses of the ETMy QUAD. Then we,
Secured the ACB locking bracket and used the wedge to swing it back and prop it into place. See notes on this in attached alog.
Attached the FC QUAD cone to the structure and sprayed FC (standard 3 coats) on the HR surface.
Removed the cone from the suspension. Finished FC layer reinforcement.
Removed the wedge from the ACB and restored it's nominal hanging position. Removed the ACB locking bracket screws.
Started stowing all left over bags of "junk" left outside of the chamber door on various table surfaces by SUS and every other team that visited this last month. If you're missing something (and you noticed), I took ownership of it.
Jim arrived and unlocked the ISI. The ETMy QUAD will remain locked during dome replacement.
Apollo started gearing up to remove walking plates from upstairs and crane the dome on the chamber.
Tomorrow's to-do list which Margot and I will do until the last step:
Inspect insides of viewports.
Adjust ACB to check magnet gap which may or may not have shifted slightly due to the swing back from today.
Clean the chamber, vacuum, etc.
Take final PCL swipes.
Blow various other optic surfaces. Or not.
Swap in final 1" witness optic on QUAD structure.
Check/Remove all tools.
Remove ETMy-HR with N2 blow.
Set and lock all 64 QUAD EQ stops and nuts, accounting for buoyancy.
Set QUAD BOSEMs to account for buoyancy.
Quick QUAD health check with DTT TFs.
Lay final witness plates.
Exit chamber.
Finish stowing everything around door and move it out of the way.
Put door on.
So, when we went to swing back the ACB and stuff the wedge into place, the wedge could not be inserted in the gap all of the way due to interference with the round balance weight attached on top of the baffle. We pushed the wedge in ~2/3 of the way which gave us ~2/3 more working area than we had with out swinging it back at all. Good enough. (Removing the round weight would have cause the balance of the ACB to be out of alignment so that wasn't an option.) Also, even though the locking bracket was engaded which provided some support to the down tube of the ACB, the ACB was still a bit "rickety" during this maneuver.
The first picture below is of the ACB wedge not quite installed as far in as it could. This meant that the screw holes to secure the wedge in place could not be engaged. ACB engineers must have anticipated this so they provided us with a "safety" chain which one could tie up "somewhere" such that the wedge doesn't come flying out at you if you bump the baffle while it's up. The chain was of limited length, so they best Margot and I could do was wind it around the post loosely a few times. Note, the wedge seemed wedged in well enough that it didn't budge when we did happen to bump the baffle a bit here and there with the cone work.
Also note, the ACB did not hang the same way after we restored it. Mitchell had to make some minor tweeks to the balance today in order to recover the correct gap setting for the magnets (specifically 0.09 inches! - Really? Not 0.08" or 0.1", but 0.09", huh!? Seems a bit tight given the grossness of both the swing back application and the shear size of the baffle... but what do I in SUS know.) In the end, as usual the ACB comes with in a few mm of the QUAD structure at the head of one of it's screws (see 2nd picture with red circle around it).
Here is an update on the instruction for untripping seismic, with some new tips from Fabrice, especially for ETMX.
Untrip HEPI WD, use Commands2 window to isolate level 1 on all chambers except BS which is level2
Untrip ISI WD (you may need to raise T240 Threshold)
reset CPS offsets,
Check that everything is in high gain: (this is also good to check if you are already isolated but have a lot of motion)
If you have been struggling with switching the blend filters, you may want to zero the T240s. You can do this in the three T240 screens by tuning on the AutoZ filter module in the X filter module, then turning it off.
Use commands, isolate level 3 for most chambers. For ETMX start with Commands, Isolate Stage 1 Level 2. Once this script is finished, isolate stage 2 level 3.
Switch Blends:
good luck...
We just tried again. The following sequence seems robust for ETMX:
a) Isolate Stage 1 Level 2
b) Isolate Stage 2 Level 3
c) Swith Stage 2 to TCrappy (Using Switch All)
d) Swith Stage 1 to TCrappy (Using Switch All)
We are working on the Guardian to simplify all of this. It will handle all the parameters and sequences specific to each chamber (controls level, blend filters, alignement dofs to be restored...)
If you have been struggling with switching the blend filters, you may want to zero the T240s. You can do this in the three T240 screens by tuning on the AutoZ filter module in the X filter module, then turning it off.
It is my understanding that you should NOT zero the T240, certainly not just to try it. In a new installatioin or the T240 is suspected of being out of level, then one should look at the U V W signals and AutoZ if they are not close to zero once the machine has stabilized. Before I was told this, it was my experience that pressing the AutoZ did NOT speed up the Trillium settleing process. Rich Mittleman--please weigh in here.
I agree with Hugh that re-zeroing the T240 should not be done while the T240 is in the midst of settling from a large dynamic shift. The re-zeroing is used to reset the mass-center of the instrument. This can shift with temperature or DC level changes. One should be sure the instrument has fully stabilized, otherwise you run the risk of 'recentering' to some off-center location. the Manufacture's (Nanometrics) instuctions can be found in section 2.4.2 of the T240 OBS manual (1). https://dcc.ligo.org/LIGO-T0900323 (2) -Brian (1) OBS - Ocean Bottom Seismometer. we use this because it is smaller, and we provide our own pressure vessel. (2) yes, we have received permission to put a copy in the DCC.
Thank you for clarifying...
Fabrice asks that we also add a step at the begining of the procedure where we plot the WD trip, zoom in and post it in the alog. Hopefully this we result in seismic people analyzing them and figuring out why we have so many trips.
This is important because our current rate of trips (and the time it takes to recover from them) will be a serious impediment to commsioning once we need to use 7 chambers all at the same time.
Shocking, I know. While exploring data from last night (see LHO aLOG 11026), I saw what looked to be artificially clean straight lines through the performance of the ISIs. In order to confirm, I switched the windowing function in DTT from the default Hann(ing) to "BMH" (which I think is the Blackman-Harris Window), and indeed the reported ASD at those frequencies where the spectra looked artificial changed. Sadly, with this particularly huge dynamic range of a signal, the spectral leakage artifacts hide the real signal right at the frequencies where tilt bothers us (~0.5 to 10 [Hz]). I also tried the Flat Top window, and that seems to be the best for X DOF which has high dynamic range, but in RY, which doesn't, it "over" estimates the ASD at 0.05 [Hz]. Unclear whether this is a good compromise given that depending on the hour, we're interested in one band or the other affecting the performance. So, I guess I'll have to use asd2.m found here because "[when not computationally limited,] the spectral [leakage] of a single, long-time window is much smaller than the spectral [leakage] of many short, overlapping windows (like you get with pwelch)". Which really means we should just get the live noise budget up and running. #yakshaving
Aidan, Dave H, Thomas More cabling and plumbing. The leaky laser from ALOG 11019 was replaced with a new one and a matching RF driver. We're in a position to be able to turn on the laser mid-morning tomorrow.
All view ports on the spool between BSC 6 & 10 were removed and replaced with blanks and torqued. The dome went on BSC 10 and 90% of the bolts were inserted with 4 of them snugged with the remainder to be tightend tomorrow morning.
The new ITMx monolithic welding has been successfully completed and was left suspended overnight last night. The majority of the modal measurements have also been completed today, with the exception of the violin modes, which are proving to be trickier to measure than in previous suspensions. We will continue with these measurements tomorrow with some different equipment. Stay tuned for subsequent posts with IAS and modal measurement numbers.
Modal frequencies of the test mass (ITMX) with the PUM nominally locked are:
ITMX
value resolution
Pendulum 0.649 0.002
Pitch 1.1153 0.002
Yaw 1.0928 0.002
Bounce 6.74 0.016
Roll 9.195 0.016
Violin modes fibre serial number
BR 499.9 0.06 S1400155
BL 501.2 0.06 S1400156
FR 500.8 0.06 S1400138
FL 502.2 0.06 S1400153
[just as a note to self as much as anything - remember to use the Uniform window on the spectrum analyser for the violin modes when using the chirped sweep output]
Forgot to post this last week. Final alignment numbers from the ITMx welding (all directions/rotations reported from the view of the IAS equipment, i.e. looking at the HR face of the ITMx):
08:57 Aidan and Dave H. working on TCSX table enclosure 09:14 Jeff and Andres working on SR3 09:34 Corey to end X TMS lab to bag and inventory parts 09:53 Jeff done working on SR3, Andres finishing up 10:18 Betsy going to work in LVEA test stand 10:20 Jim done taking measurements on end Y ISI, to end Y to work on cable routing 10:24 Jax transitioning end Y to laser safe 10:29 Hugh to HAM4 to install vertical L4Cs 10:30 Kyle to crane RGA over YBM (WP 4529) 10:41 end Y is laser safe 11:07 Kyle done craning 11:59 Andres, Arnaud starting transfer function measurement on SR3 12:00 Guardian code is running on ITMY ISI 12:36 Betsy and Margo leaving to go into BSC 10 12:47 Karen going to end Y to clean in VEA 12:59 Ski to end Y (not in VEA) 13:04 Tour in CR 13:45 Ski back from end Y 13:49 Dave H., Aidan and Thomas starting work again on TCSX 15:05 Karen back from end Y 15:25 Dick and Jax going to end Y to install electronics, too much other work going on, left electronics there 15:46 Apollo installing dome at end Y High dust count alarms at end Y most of the afternoon, parties involved informed
I have started an rsync of the /opt filesystem on h1boot, to the new backup boot server starting at 16:14PDT. The filesystem on h1boot may be a little slow while the transfer runs, on a timescale probably measured in hours as it is about 300GB of data.
Mitchell with Apollo help until lunch, The newly assembled optical table was moved and placed on stage 0. After lunch I shopped for the parts at the interferometer emporium, moved the Stage 1 base plate onto the granite table and attached the plate flipping gear.
Laser is on Output power is 28.1 W (should be 30 W) Watchdog is active No warnings in PSL SYSSTAT.adl other than "VB program online" PMC Locked for 4 days 3 hours (should be days/weeks) Reflected power is 12.7% of transmitted power (should be 10% or less) FSS Reference cavity is not locked Trans PD threshold is .4 V (should be at least .9 V) ISS Diffracted power is around 7.8% (should be around 10%) Last saturation event was 11 minutes ago (should be days/weeks)
