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. 

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.

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.

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.

Set the SEI in this state at 1918pdt.

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.

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.

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.
 

The HEPI stops at BSC10 were pulled back for the next phase of the DetChar study.  However, Jeff and Guillermo are running some TFs before it goes into the nominal state for DetChar.

The HEPI is now Isolated and the ISI is High_Isolated both stages,

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

Kiwamu and Dave.

We rebuilt h1lsc using RCG2.8.4 and restarted the model. We found that the "LOAD MATRIX" button is intermittent. 

The DAQ status of h1lsc is now 0x2000 due to the channel type change. Kiwamu says its ok to leave it like this until the next DAQ restart.

ITMY
- lock ISI
- FC on
- FC off
- Unlock ISI
- Clean

ITMX
- FC off
- Wipe

ITMY Spool
- finish CPB work

PR2
- Take a look at it from BSC2

HAM6
- Install VP on septum

ETM09
- Close out

The HAM-ISI and HEPI MEDM screens were updated to match the latest IOP Dackill part naming convention. Details can be found in the SEI aLog entry #510

Work was performed under WP #4765 (signatures collected by Arnaud), which can now be closed.

Yesterday with the help of Apollo the CPB was successfully installed. This morning the final balance and alignment was completed.

DAQ was restarted to:

use the latest Beckhoff INI files (EY illuminator and HWS additions)

resync h1odcx FE data following PCAL additions.

After first verifying that no critical measurements were being taken, I performed an nmap port scan of the H1FE VLAN. This caused the daqd process on h1broadcaster to fail, it was subsequently restarted by monit.

I ran the port scan a second time, and h1broadcast0 daqd did not fail this time.

The log files show a correlation between port scan and the failure. I will exclude all DAQ hosts from future port scans.

The ODC went red at 0808pdt when the guardian took the Stage2 of the ETMy ISI from HIGH_ISOLATED to DAMPED.

HEPI at EndY remains on stops ith the MasterSwitch open; its ODC is red.