ETMX (QUAD) L2 (PUM) UL channel excess sensor noise appears due to in-vacuum cabling

[Gary T, Danny S, Matt H, Stuart A, Norna R]

During the close-out work of the BSC9 chamber (see LHO aLOG entry 13085) we were able to further investigate the source of the excess noise that had previously been observed on the ETMX (QUAD) L2 (PUM) UL channel (see LHO aLOG entry 13047).

Previously, I had swapped field cables at the Satellite Box between ETMX L1 and L2 stages running to the chamber. This indicated that the noise was downstream, i.e. with the field cables themselves or in-chamber. We repeated this test, but this time swapping field cables at the air side of the vacuum flange. Further measurements then eliminated the field cables and confirmed the issue resided in-chamber.

Gary inspected and re-seated the in-chamber connectors from the vacuum flange to the OSEM, but this offered no improvement. Finally, the L2 UL AOSEM (s/n #270) was removed and a spare unit connected up in it's place, but again, unfortunately this offered no improvement.

This indicates that the excess noise is most likely a in-vacuum harness problem, which would be invasive to attempt to replace. Therefore, it was decided to generate an integration issue and proceed with the close-out of the chamber, with the excess sensor noise on this channel.

Integration issue generated, see Bug #929.

Irises removed from the OFI

Gerardo, JeffB, Mike, Hugh, Travis, Appollo, Kiwamu,

We have removed two irises from the output faraday isolator (OFI). They were originally meant for a temporary tool for aligning the OFI and we simply forgot to remove them. So we opened up the HAM5 north door and locked the north side of the ISI. Then we took out the two irises -- one at the input side and the other at the output side. Note that we left the irises' holders attached. Also, Gerardo replaced the holder at the output side with a clean one because the one we had was not class-A compatible.

After unlocking the ISI, Hugh checked the balance of the ISI and he did not see a significant change. So we did not have to put a counter weight as expected.

We revisited the HMA5 installation exit check list, performed those activities and found nothing special. So it is good.

Some pictures will be uploaded later.

H1 EX T240 Rotated 90 [deg], GND PEM Guralp Moved back into PEM Stay-Clear Zone

J. Kissel

I've aligned the GND T240 to the global IFO coordinate system (see LHO aLOG 12930 for discovery of mis-alignment). Further, in preparation for the UWash tiltmeter install, I've returned the PEM Guralp floor seismometer to inside the stubs of the PEM stay-clear zone.

--------
Details

Alignment / Leveling:
PEM's Guralp - The instrument doesn't have any holes for an alignment rod, so I had to align the instrument by eye. I've pointed the "North" direction (alignment nub near the the bottom of the instrument) in the IFO's +X direction (as it was already, in its previous location). I've also re-leveled the instrument, and re-covered it in its thermal shield. See first three pages of attached pictures. 
GND T240 - I used a brand new alignment rod "swizzle stick" (thanks Hugh!) to align the "North" direction in the IFO's +Y direction. See pgs 6-8 of attached pictures. (Hugh gave me a borehole micrometer with rounded tips to better measure the inner-diameter of the T240 alignment rod hole. It measures 0.315 [in] = 8.001 [mm]; consistent with what had been previously measured using flat-edged calipers; see pg 4-5 for pictures.)

Quantitatively confirming that the instruments are co-aligned with each other, and aligned well with the global IFO coordinates is difficult, at best, since there's no good alignment reference in this area. In attempts to quantify it, I've attached the coherence between each of the ground instruments and the T240s on the ISI in chamber. At the time, the platform had ST1 isolated and ST2 watchdog tripped (and I didn't check the status of HPI, but presumably if ST1 was isolated, HPI was robust isolated). That the platform was isolated sort of ruins the analysis, but it's something. Will ask the seismic team for advice.

Centering:
After moving/rotating the T240, the output signals remained saturated for ~5-10 minutes; not un-expected -- I've had the same experience with STS2s I've commissioned. Anxious to see if the instrument was saturated or rail/broken because of the move, I centered the instrument using the "Auto Z" button on the 4th chassis down (U18 of SEI-C1 rack -- see pg 9-11 of pictures), and the instrument went to zero within a second of the button push, but then veered off into lala land again shortly after. Waiting a few more minutes, and the signals came back into the ADC range. It still did not settle to zero mean within another 5 minutes, so I zeroed the instrument once more. Time series behavior was the same, so it just takes many many minutes to really settle. Again, no surprises here.

Calibration:
Sensor              Calibration
ISI T240s     1e-9      [(m/s) / (nm/s)]
GND T240s     1e-9      [(m/s) / (nm/s)]
PEM Guralp    7.6e-8    [(m/s) / ct]
pem.ligo.org suggest the calibration is "0.0076 [(um/s) / ct]," or 7.6e-9 [(m/s) / ct]. However, plotting this against the well-known (by my at least) calibrations of the T240s, the quoted PEM calibration appears low by a factor of 10. Hence, my calibration above. 

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.

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.

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.

Overdue update on Sunday work

Calum, Rich, Matt

 

HAM4

The soft cover on the South door was not billowing at all. Despite the obviously low purge air and Matt working in HAM4, the initial particle counts were low. Before starting work, I wiped down everything I could reach with a pre-wetted wipe. Calum and I inspected the optic with a green flashlight (not to be confused with the Green Lantern, D1400060). For both faces of SR2, we estimated 25-100 particles per square inch depending on the region. BEFORE applying FC, we found a ~1 inch piece of leftover FC from the alignment layer on the HR side, and what appears to be a long strand of FC on an earthquake stop. There were numerous glove prints and leftover FC on both faces near the barrel. Because the HSTS legs are warped from welding, we had to use 2 washers on a side of the spray cone bracket to keep the cone on its intended track. Not surprisingly, the particle counts spiked while spraying FC. The "CAL Alarm" popped up on the count taken while spraying. I need to look up the settings for the handheld particle counters to check what that means. The FC appeared much thinner and had more bubbles than usual, but there were less cobwebs than we observed on Saturday. We moved on to HAM5 to let the FC dry.

Matt returned later to retract then remove the spray cone. The wipe on the end of the cone stuck against the optic when the cone was retracted. This has never happened before at either site, not even when a cone was left on overnight. I used the same procedure (E1300017) as always. Matt pulled very gently on the wipe, and it separated from the optic. I painted 3 layers of FC around the edges and added a PEEK tab. The painted crust was much darker in color than the sprayed FC.

	Outside chamber  (before work)	Inside chamber  (before work)	3 mins after 1st  FC layer	While spraying   2nd FC layer	3 mins after 2nd FC layer	5 min after 2nd   FC layer	3 min after last    FC layer	Outside chamber (before painting)	Inside chamber (before painting)	Exiting (Matt)
0.3 um	10	70	70	918200	4330	670	1380	10	200	850
0.5 um	0	20	20	749920	3030	500	1010	0	40	380
0.7 um	0	20	20	586250	2310	340	750	0	30	270
1.0 um	0	10	20	466730	1630	270	600	0	20	170
2.0 um	0	10	20	293620	830	170	340	0	10	70
5.0 um	0	0	0	62590	60	10	40	0	0	30
RH (%)	35	22	27	30	28	34	27	39	20	31
Temp (F)	75	75	72	73	73	73	73	75	70	70

 

HAM5

Like HAM4, there appeared to be very little purge air. Spraying SR2 with FC only a few minutes earlier likely caused the high initial particle count in HAM5. SR3's HR side had 10-30 particles per square inch and a big streak of FC from the alignment layer plus small bits of FC near the barrel. SR3 was sprayed on Saturday. A modified mix with slightly more thinner was used for the 1st layer in an attempt to reduce cobwebbing. It worked, but there was more backsplash (contained by the cone). The standard 1:1 mix ratio of FC and thinner was used for the 2nd and 3rd spray layers.

On Sunday, we removed the cone and painted the crust on SR3. The dried FC spray looked uneven and runny.

	Outside chamber (before work)	Inside chamber   (before work)	1 min after     painting	Exiting HAM5   (Matt)
0.3 um	0	780	320	140
0.5 um	0	390	130	50
0.7 um	0	170	40	30
1.0 um	0	100	30	0
2.0 um	0	60	10	0
5.0 um	0	0	0	0
RH (%)	35	35	33	39
Temp (F)	74	75	70	71

 

BSC2

The beamsplitter was absolutely filthy, and had over 50-100+ particles per square inch. There were tiny circles all over the HR side that looked like rings left by evaporation. There were noticeably more fibers on the AR side. Both faces had glove prints and lefover FC near the barrel. I didn't get any good pictures unfortunately.

I sprayed both faces on Friday, and painted the crusts on Sunday. Like SR3, the FC on the BS was extremely runny.

	Outside BSC3   (before work)	Inside BSC3     (before work)	Inside BSC2     (before work)	Exiting BSC2
0.3 um	70	130	190	360
0.5 um	50	50	120	260
0.7 um	30	30	100	250
1.0 um	20	10	100	230
2.0 um	10	10	70	200
5.0 um	10	0	70	110
RH (%)	36	18	20	20
Temp (F)	71	71	73	69

 

I'll add photos soon.