BSC9 - TMSX (TMTS) M1-M1 (top stage) TFs are clear

DTT TFs were taken on the TMSX (TMTS) suspension this morning, to check for signs of rubbing etc following close-out of the BSC9 chamber (see LHO aLOG entry 13117), as follows:-

- TMSX M1-M1 undamped (2014-08-01_0730_H1SUSTMSX_M1_ALL_TFs.pdf)

BSC9 ISI Status: ISI damped and ST1 high isolation.

TMSX alignment: No offset was applied during this measurement.

The above measurements have been compared with the 'best' performance previously obtained for H1 TMSX i.e. taken in-vacuum (alltmtss_2014-08-01_Phase3a_H1TMSX_M1_Doff_ALL_ZOOMED_TFs.pdf), the plot key is:-

Blue Trace = Model Prediction.
Orange Trace = H1 TMSX M1 (2014−05−09_1083659254), Phase 3b (in-vacuum).
Black Trace = H1 TMSX M1 (2014−08−01_0730), Phase 3a (in-air).

Summary:

Following chamber close-out TMSX appears healthy with no indications of rubbing. Also, compared to previous measurements TMSX looks to be performing very well, with no sign of split transverse peaks that we had seen in the past. Therefore, these TFs raise no concerns.  

All data, scripts and plots have been committed to the sus svn as of this entry.

X1 pressure accumulation exercise complete -> Opened GV14

Pressure gauges PT134B, PT144B, PT343B and PT344B should recover to their nominal values in the next few hours and alarms treated normally

BSC9 - ETMX (QUAD) M0-M0 & R0-R0 (top stage) TFs are clear

Matlab TFs were retaken on the ETMX (QUAD) suspension overnight, after DTT TFs taken earlier on the afternoon had shown no signs of rubbing, but had some ratty zeros (see LHO aLOG entry 13126), as follows:-

- ETMX M0-M0 undamped (2014-08-01_1090893895_H1SUSETMX_M0_damp_OFF_ALL_TFs.pdf)
- ETMX R0-R0 undamped (2014-08-01_1090911928_H1SUSETMX_R0_damp_OFF_ALL_TFs.pdf)

BSC9 ISI Status: ISI damped and ST1 high isolation.

ETMX alignment: No offset was applied during this measurement.

The above Matlab measurements have been compared with the latest DTT TFs (allquads_2014-07-31_H1SUSETMX_Phase3a_Doff_ALL_ZOOMED_TFs.pdf), the plot key is:-

Blue Trace = Model Prediction.
Orange Trace = H1 ETMX (erm 2014−07−31), Phase 3a (in-air).
Black Trace = H1 ETMX (erm 2014−08−01), Phase 3a (in-air).

Summary:

The overnight Matlab TFs are much improved, showing higher Q's, and better defined zeroes, most importantly they raise no concerns for the top stage of ETMX following chamber close-out.

All data, scripts and plots have been committed to the sus svn as of this entry.

ETMY HEPI pier amplification - floating vs locked

Summary - floating HEPI has significant improvements in the X and Y directions, the peak frequency of the effect shifts from ~11 Hz to ~8 Hz and reduces the magnitude of the resonance by ~an order of magnitude.

Thanks to Hugh, who put HEPI in all three states (see alogs - 13077, 13103, 13129), I've looked at the HEPI pier resonance at ETMY; I wanted to see the benefits of floating HEPI. I've taken one hours worth of recent data from when HEPI was locked/floating and compared the ground motion recorded by the STS2 (H1:ISI-ETMY_ST1_SENSCOR_GND_STS_X/Y/Z_FIR_IN1_DQ) to the top of the HEPI piers by the L4Cs (H1:HPI-ETMY_BLND_L4C_X/Y/Z_IN1_DQ). Attached is a plot showing the ASD ratio of the L4Cs to the STS2 for when HEPI is both locked and floating. Floating HEPI has significant improvements in the X and Y dorections only, the peak frequency of the amplification shifts from ~11 Hz to ~8 Hz and reduces the magnitude of the resonance by ~an order of magnitude. This is very similar to what we see at BSC1-3 at LLO (https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=13828). Comparing times when HEPI is locked, ISI is isolated and times when HEPI is locked, ISI St1 is isolated and St2 is damped do not appear to show much difference.

To see more on this study (and more plots) see: https://dcc.ligo.org/G1400820

NOTE - Data is still not being saved correctly to the H1:ISI-GND_STS_ETMY_X/Y/Z_DQ channels (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=12818), hence why I've used the SENSCOR channels.

ETMY HEPI 8ishHz Peak

This plot is interesting.  It seems the only moderately pronounced peak in the horizontal ground spectrum wanders, seen from 8 to 11hz changing quite rapidly.

The attached plot's current traces are with HEPI loops closed and the ISI Damped.  While the middle graph shows all four local IPSs have the strong 8hz peak (the dashed REFs are with the HEPI loops open), the peak only shows in the X & Y and not the RZ cartesian traces (top graph).  Also, note the bottom graph where the ground sensor pretty much has nothing at 8hz but does have a minor peak just above 9hz that is also peaking up in the local sensors.

The second plot shows just the ground Seismometer with X & Y traces from last night (Dashed) and the others from this morning. The peaks in that area come and go and wander around so it may or may not be a problem or just a red herring (are those edible?)

I am attaching the spectrograms for the X, Y, and Z directions of the STS Seismometer in ETMY.
I used 19 continuing hours, starting 2014-07-22 01:00:00 UTC.

There is a feature that is present all the 19 hours:
Around 10.5 Hz  in X direction.
Around 9 Hz in Y direction.
Around 10.5 Hz in Z direction.

More features can be seen wandering along the 19 hours around 3-5 Hz and 8-10 Hz, for X, Y, and Z directions.

In the spectrograms, each count is 1 nm/s /sqrt(Hz).

Continuing with the investigation on the 8 Hz, I am attaching the spectrograms for the X, Y, and Z directions of the GND STS in EY.

Comments on the spectrograms: 
- Feature wanders between 7.5 to 12.5 Hz.
- Depends on the time of the day. 
- It is present every 15 to 30 minutes.
- Displacement amplitude higher than 2 nm.

6 hrs were used for each spectrogram, starting:
- August 01, 2014 00:00:00 UTC (Figure 1)
- August 01, 2014 06:00:00 UTC (Figure 2)

The 8 hz motion seen here is most likely related to the "pier resonance" 
Laura Nutall has a nice set of plots in the DCC https://dcc.ligo.org//LIGO-G1400820
which show this motion. 
Likely you are seeing the floor component of this motion. Rich M. has data showing that (at MIT) the slab bending is an important component of this motion

I investigated the GND SDS and PEM MIC channels using the coherence tool at 100mHz bandwidth and found several peaks between 5 and 9 Hz. I've attached some slides with zoomed-in plots.

Morning Installation Meeting Minutes

• Will most likely start pumping down Mon (instead of today)
• Ymanifold spool---installing this morning
• HAM5 door removal after Spool (to remove irises on SUS--a quick 15min job) & re-install
• On Mon make sure there are no other gotchas like these irises before pump down
• BSC2/1 First Contact work and sealing up BSC1
• viewports work by Gerardo
• HAM6:  Koji & alignment start next week
• bugzilla:  aaai chasis work at all bldgs
• kills switches for lasers & high voltage work

CDS model and DAQ restart report, Thursday 31st July 2014

model restarts logged for Thu 31/Jul/2014
2014_07_31 09:45 h1broadcast0
2014_07_31 10:08 h1broadcast0
2014_07_31 10:08 h1dc0
2014_07_31 10:08 h1fw0
2014_07_31 10:08 h1fw1
2014_07_31 10:08 h1nds0
2014_07_31 10:08 h1nds1
2014_07_31 13:43 h1lsc

unexpected broadcaster restart due to port scanning. DAQ restart for config upgrade, LSC testing of rcg2.8.4 ramp-mux-matrix.

H1 SUS PR2 -- More Evidence of Bad In-vac Cabling, but it's the Sensors

J. Kissel, A. Pele, S. Aston, N. Robertson

Not too much more information here that we don't already know, but I think I've convinced myself that the badness we see on H2 SUS PR2 is *only* a function of the OSEM sensor, and not the actuator -- end hence it's just an exaggerated high-frequency turn-up that we've seen in every other OSEM to OSEM transfer function, and it's caused by the in-vacuum part of the signal chain. Since we don't use the *sensor* side of the OSEM for any active feedback, and we have no evidence the *actuator* side is broken, we should *NOT* need to go back in chamber to fix the cabling this vent.

The new evidence, and summary of old evidence: 
- I've used the test-point versions of the OSEM Basis channels, such that I could probe the transfer function behavior out to 5 kHz. Also, I plot the phase coherence, and the other OSEMs. If the suspension was actually being driven that much at 45.25 [Hz] (i.e. it was an actuator problem), then the other OSEMs should definitely have coherent response. This was already proven when Arnaud drove L, and so only LR respond badly (see LHO aLOG 13026). Another feature also appears at 787 [Hz] -- not a multiple of 45 -- and really not indicative of anything other than the in-vacuum signal chain is busted. We know it's the in-vacuum cabling, because the badness stays with the port when external cables are swapped (see LHO aLOG 13087).
    
- I've compared PR2's M3 spectra to several other HSTS M3 stages. Stuart only looked up to 50 [Hz] (see LHO aLOG 13106), but looking out at high frequency, PR2 should all sorts of crap in every M3 channel. All other SUS at which I looked show a nice, super clean noise floor save the expected violin modes at 350-400 [Hz] (at though sadly increasing above 1 [kHz] as roughly f^2). I had thought, briefly, that this PR2 feature was the highest Roll mode (modeled at 40.3 [Hz]), but Norna convinces me that, for a SUS whose other modes line up to within 1-2%, its unreasonable that only one mode would be off by 12%. Further, one would see such physical motion in all 4 of the OSEMs, and one does not here. Also, no other suspension sees any such feature at that frequency, and at LLO, their LSC_MC filter bank (in the IMC length control feedback path) has a roll notch at 40.9 [Hz].

Our best guess at the source of this problem in-vacuum shorts or poor cable connections caused by all the activity in-and-around the chamber during this summer vent. 

ITMY lower stages results

Lower stages transfer functions were taken on ITMY suspension last night, while the suspension and the ISI were unlocked. During the measurement, the ISI was damped, the reaction chain damped and the main chain undamped. Results are attached as described below :

1. UIM TFs  (L1-L1)
2. PUM TFs (L2-L2)

Results look fine except the fact that they are off by a factor of 2ish (meas=2*model), which seem to be the case for other quads as well. Data was noisy for the L2 stage so I increased the drive amplitude and will run it again after closeout.

I caught other calibration issues in the process. First was a factor of 10 in the L1 sensalign matrix, the second one was a wrong factor in the matlab script "plotmatlab_tfs.m" to compensate for the transimpedance of the recently modified coil drivers.
A new safe.snap was made and commited under the svn as well as data and script.

EndY BSC10 HEPI RingUp around 8/9 Hz

JeffK HughR

Jeff will likely have more coherant things to say but the engagement of the X & Y HEPI loops rings up around 8 or 9 Hz.  They may each have there own of these--too tired to be sure.  Will continue looking tomorrow.

The ground STS2 has some motion at these frequencies and the tall BSC SEI Pier Resonance is in this area so, it may be the peak on the ground or the X & Y loops themselves or in combination with the ground and Pier.

The attached spectra shows the peak rung up on the Y DoF.  The reference is with both X & Y off and all other SEI loops are closed (ISI HighIsolated & rest of HEPI closed loop).  The plots of the ground STS2 with references shows how this power changed within a short time.  The lower left shows the peak in all Horizontal IPS sensors suggesting it is indeed coming from the ground.

I was just out to the EndY this afternoon and things are pretty quiet.  However, given that this HEPI has been sort of locked for a few months, I can't say that the position loops have ever been robust at these frequencies.

More study tomorrow.

Hugh sums up what we've found nicely; not much more to add. I attach a time series of the actuator trip.

Hugh showed me the loop design plots, and they don't look like a bad design. There may be a sharp feature in the plan around 8 [Hz] that's not resolved, and around 8 [Hz] is where the gain peaking is the largest, but it's predicted to amplify the motion no more than a factor of 1.585 at 8.35 [Hz]. 

Strangely, I didn't find nearly as many loop design plots for X as for Y in the 
/ligo/svncommon/SeiSVN/seismic/HEPI/H1/ETMY/Data/Figures/Transfer_Functions/Simulations/Isolation/
but the MIMO plot I did find seems to confirm that the gain peaking should be similarly small.

Remember, though -- all of these models are based on ONE local-to-local measurement. Perhaps the HEPI plant (including the state of the ISI) has changed since these were last measured... There's certainly been a whole lot of action with the position locking stops recently, see LHO aLOGs 13070, 13077, 13123, but I'm not sure how stops would create any sharp feature that would create a slowly evolving positive feedback loop at 8/9 [Hz] especially -- but as Hugh points out, this feature is right-around the HEPI pier resonances.

ETMX (QUAD) M0-M0 & R0-R0 (top stage) TFs show no obvious signs of EQ rubbing

Jeff K last night took TFs on the ETMX (QUAD) declaring it "Go for launch" (see LHO aLOG entry 13098), doors have subsequently been fitted on the BSC9 chamber this afternoon (see LHO aLOG entry 13117) and I've taken another set of TFs this afternoon as follows:-

- ETMX M0-M0 undamped (2014-07-31_1500_H1SUSETMX_M0_ALL_TFs.pdf)
- ETMX R0-R0 undamped (2014-07-31_1500_H1SUSETMX_R0_ALL_TFs.pdf)

BSC9 ISI Status: ISI damped.

ETMX alignment: No offset was applied during this measurement.

The above TFs have been compared with Jeff K's measurement from last night (allquads_2014-07-31_H1SUSETMX_Phase3a_Doff_ALL_ZOOMED_TFs.pdf), the plot key is:-

Blue Trace = Model Prediction
Orange Trace = H1 ETMX (erm 2014−07−30), Phase 3a (in-air).
Black Trace = H1 ETMX (erm 2014−07−31), Phase 3a (in-air).

Summary:

ETMX peaks appear consistent with the previous measurement, before putting the doors on, thus indicating that there is no rubbing present. However, some of the zeros still appear a little ratty, especially in L and T DOFs on both chains. This could be due to turbulence due to purge air. 

Therefore, I plan to repeat this measurement overnight, but this time using a Matlab TF and enabling ST1 isolation loops on the ISI.

All data, scripts and plots have been committed to the sus svn as of this entry.

EndY BSC10 SEI State fot DetChar--HEPI Free/ISI St1 Isol, St2 Damped

Set the SEI in this state at 1918pdt.

Matlab TFs running on ETMX (QUAD) overnight

Matlab TFs are set to run at the X end station overnight as follows:-  

- ETMX (QUAD) M0-M0 undamped TFs
- ETMX (QUAD) R0-R0 undamped TFs
- ETMX (QUAD) L1-L1 undamped TFs
- ETMX (QUAD) L2-L2 undamped TFs

Starting now, and when complete the measurement status will revert to OFF and damping loops will be restored to the ON state.

Also, note that I have transitioned the BSC-ISI ST1 from DAMPED to HIGH_ISOLATED via Guardian, thus enabling ST1 isolation for this measurement.

These measurements have been initiated from the opsws2 workstation.

BSC3, 2, 1 closeout status

This morning after Jim locked the BSC1 ISI, I applied First Contact to the ITMy CP-AR surface via the spray cone technique.  We then made final preps to the SUS locking down nuts, closing the ring heater, etc.

 

Particle counts in chamber before we started, but after Mitch had walked through for access to the X-spool ~an hour earlier:

0.3um  30

0.5um  10

1.0um  10

 

Particle counts after FC spraying was done, taken nearish door ~10 mins after spraying complete, 3 people working in chamber:

0.3um  840

0.5um  430

1.0um  260

 

Greg also looked at the TCS mirrors in BSC2 while we were there - more from him later I suspect.

We wiped our way out of BSC2 and BSC1.

I then went into BSC3 and wiped the floor.

We broke for lunch. 

After lunch we used the N2 gun and removed the FC from the CPx-AR and ITMx-HR.  We then alternated blowing on the ITMx-HR and gap between optics for 1 min intervals until each set of surfaces had seen ~5min of N2 deionization at 10psi.  I blew the barrels a little while as well.

 

After unclamping the TM and CP, we set the 1" witness optic and the 3" witness plate on the QUAD SUS and 1 3" WP horizontally on the floor in the center of the chamber.  A quick check of TFs in V, P, and T showed a healthy suspension, so we closed the BSC3 door.

 

Moving down to BSC2, we pulled the FC on the BS-AR.  It tore across the top and then as we pulled it down across the optic it left 2 ~2mm chunks of FC in the center ~4 inches of the optic.  We determined that we would need to respray clean this surface (phiszzll) so we aborted the BSC2 and BSC1 chamber closeout.

We pulled the BS-HR FC to make sure it wouldn't leave anything else either.

Jim locked the BSC2 ISI again and we mounted the FC spray cone to respray FC on the BS-AR and HR surfaces.  We reinforced the edges of the sheets with paint-on FC as usual.  Tomorrow we will reattempt to pull the BS and ITMx FC sheets and move on to close these chambers.

Ops Summary

8:39 am, Jordan and Paul to visit beam tube between Mid and CS.
8:47 am, Gerardo to CS VEA, HAM6 viewport septum install.
8:57 am. Andres to CS VEA, beer garden retrival of parts/hardware.
9:06 am, Jim to CS VEA, BSC1 lock ISI.
9:23 am, Jordan and Paul to Y-End station to install microphones.
9:43 am, h1broadcast0 crashed, restarted itself after few minutes.
9:44 am, Stuart to X-End VEA.
10:11 am, DAQ restart.
10:32 am, Danny to X-End VEA.
10:40 am, Stuart to X-End.
10:44 am, Jeff to CS VEA, cleanroom by HAM4.
1:00 pm, Large crew to CS VEA, beer garden close up BSC3.
1:01 pm, Second crew to X-End to close out BSC09.
1:38 pm, Filiberto and Richard to CS VEA, BSC1 solder ESD pin.
1:47 pm, Jordan and Paul to Y-End.
2:58 pm, Hugh to Y-End VEA, unlock HEPI.
2:58 pm, Michael to CS VEA, beer garden to get update on closing work.
 

ETMx (BSC9) closed up

Gary T, Danny S, Stuart A, Matt H, Mark L (Apollo)

The closeup of the X-end (BSC9) is complete. Stuart has a detailed log of the timeline of the steps we did everything that he will post to this alog which gives various info on how long things took, particulates on optic, etc.

Before heading down a round table discussion (including Mike L, Norna, Calum T, Rich A, Gary T, Matt H, Danny S) looked at the information regarding the deionisation tests done at LHO and CIT and what we should do going forward in terms of using the top gun for pulling first contact. The decision was to blow between the gap of the two optics first for a smal lperiod of time (with FC still on ERM and HR of main opitc) to dislodge any large debris. Then starting with the ERM first contact, take around 2 minutes to peel this FC (blowing with top gun at the same time). Then on top of that (and starting with the ERM surface), for 1 minute blow on the ERM surface, then for a minute blow between the two optics, then back on ERM surface for another minute....and do this 9 times (for a total of 9 minutes) ending on the ERM. Thenn move to the HR of main optic. Take ~2min topeel FC here..blowing with top gun the whole time, then again starting with the HR surface, blow on this for a minute, then between the gap of the optic for a minute, then back on the HR surface for a minute (again 9 times...for a total of 9 minutes), ending on the HR surface.

 

So with this in mind, we headed to the end.

The Quad was locked

Wafers added to Quad

FC pulled on witness optic

FC pulled on ERM

Inspection of ERM surface with green light

FC pulled on HR surface main optic.

Inspection of HR surface with green light

Swung arm cavity back down

Unlocked Quad and ser EQ stops

Centered some OSEMs (BOSEMs on main and reaction chain and aOSEMs on L1 stage)

Ran quick TF's on Quad main and reaction chain to see if free

Door went on

 

Attached below is a log and particle counts taken during the BSC9 close-out work covering the period 1055 (local) to 1315 (local), as well as Danny's drawing of the first contact residue on each optic.

BSC3 ITMx status

Betsy, Travis, Andres This afternoon, we started the chamber closeout steps. We: Locked the ITMX TM and CP masses in prep for FC removal. Started to clean the barrels of the optics. Started locking down all loose nuts on the SUS. Set the BOSEMs to account for the buoyancy effect under vacuum. Assisted with TCSx in chamber mirror alignment. Prepped the N2 gun and bottle for in chamber use. Took lots of particle counts. Wiped down as mush of the VS and ITMx as possible. Wiped the floors of BSC2 and 3 numerous times. Counts were high during and just after the wiping. They did not return to zero by the time we left the chamber at 4ish. Counts data to follow. Will wipe once more before pulling the FC tomorrow morning and putting the door on.