Displaying reports 64641-64660 of 77211.Go to page Start 3229 3230 3231 3232 3233 3234 3235 3236 3237 End
Reports until 20:30, Tuesday 22 July 2014
H1 SUS
stuart.aston@LIGO.ORG - posted 20:30, Tuesday 22 July 2014 - last comment - 12:43, Wednesday 23 July 2014(12929)
SR3 (HLTS) M1-M1 Phase 3a TFs show issue with damped first vertical mode persists
[Arnaud P, Stuart A]

Following doors being re-hung on the HAM5 chamber earlier today (see LHO aLOG entry 12915), Phase 3a DTT TF measurements have been taken this afternoon for SR3 (HLTS) suspension as follows:-  

- SR3 M1-M1 undamped results (2014_07_22_1200_H1SUSSR3_M1_ALL_TFs.pdf)

HAM5 ISI Status: ISI unlocked, no damping or isolation loops running.

SR3 alignment: No offset was applied during this measurement.

SR3 undamped measurements from above have been compared with previous measurements for H1 SR3 at Phase 3a of testing (allhltss_2014-07-22_Phase3a_H1SR3_UnDamp_ALL_ZOOMED_TFs.pdf). The plot key is as follows:-

Blue Trace = Model (hltsopt_metal)
Orange Trace = H1 SR3 M1 (2014−07−15_1089513028), (in-chamber, doors open)
Black Trace = H1 SR3 M1 (2014−07−21_1090036316), (in-chamber, doors hung)
Magenta Trace = H1 SR3 M1 (2014_07_22_1200), (in-chamber, doors hung)

It can be seen that despite having gone in-chamber to improve the M3 alignment and attempt to mitigate any sources of rubbing (which we thought we had) the peculiar damping of the first vertical mode persists. Furthermore, comparing before (Black trace) and after (Magenta trace) there appears to be no improvement.

Somewhat frustratingly, before closing up the chamber, higher resolution measurements of the vertical DOF TF had indicated that the potential rubbing issue had been alleviated (see SR3_V2V_Doors_Open_vs_Closed.png).

We had considered the possibility of hanging the door may have changed the air flow due to purge air, so we carried out a measurement both with purge air on and off (SR3_V2V_PurgeAir_Off_vs_On.png), but again this failed to improve the Q of the first vertical peak.

Finally, a measurement was made with damping loops on for comparison (see SR3_V2V_Damping_On_vs_Off.png), which seems stable.

Also, last night Arnaud repeated the vertical TF while applying +/- biases to various degrees of freedom to try and check in which way SR3 could have been hung up, but to no avail.

Attached below is a log of particle counts taken during the HAM5 work covering the duration 1035 to 1126 (local).

All data, scripts and plots have been committed to the sus svn as of this entry.
Images attached to this report
Non-image files attached to this report
Comments related to this report
arnaud.pele@LIGO.ORG - 12:17, Wednesday 23 July 2014 (12941)

Also, I attached a trend of the osem signals (calibrated in um) before/after opening/closing HAM5 chamber yesterday (when Matt went in again to back up EQ stops) to show that the top mass didn't move much respectively with the cage.

Images attached to this comment
arnaud.pele@LIGO.ORG - 20:39, Tuesday 22 July 2014 (12935)

Furthermore, this V2V tf was retaken with successive +/-yaw and pitch offsets applied to the top mass. We didn't see any change (cf attached screenshot). Measurements of the lower stages will be running overnight on opsws1, which might give us some more information.

Images attached to this comment
matthew.heintze@LIGO.ORG - 07:45, Wednesday 23 July 2014 (12937)

Just in case it was lost in the mire of my earlier alog....we did low resoution Tfs with the door off initially but these showed nothing conclusive if the problem had been fixed or not. This is why Stuart dcided to try higher resoluton TFS with the door off to see if we could see if the problem had beenfixed..and from these TFs we thought we had. They mystery is why when we put the door on has it changed again ?????..hmmm puzzler.

brett.shapiro@LIGO.ORG - 12:43, Wednesday 23 July 2014 (12943)
Check the trends on the middle mass and bottom mass as well. The problem may not be at the top mass. 

Looking at the vertical mode shapes from the HLTS model:

Freq: 1.07 Hz   3.5 Hz   28.1 Hz
Top: 0.3826   -0.9250   -0.0051
Mid: 0.6524    0.2644    0.7071
Bot: 0.6543    0.2729   -0.7071

The 3.5 Hz mode is nearly all top mass motion, and that looks fine in the measurements. On the other hand the 1.07 Hz mode is dominated by motion at the lower stages.
H1 AOS (SUS)
daniel.hoak@LIGO.ORG - posted 20:30, Tuesday 22 July 2014 (12934)
Preliminary spectra and transfer functions for OM1-3

(Dan, with pointers from Jeff and Arnaud)

Yesterday and Friday I measured spectra and transfer functions for the tip-tilts in HAM6.   The transfer functions were taken with the tip-tilts in the undamped state, the spectra were taken with the damping both on and off.  The transfer functions all agree with the model.

These TTs are not in their final positions and they only have temporary dog clamps (two each, I think, instead of the nominal four, and they're not torqued to any precision), so these measurements will have to be repeated once the optics in HAM6 are aligned and clamped.

As for the OMC, Arnaud captured TFs a month ago; things looked good.

Non-image files attached to this report
H1 SYS (ISC, PEM, SEI)
jeffrey.kissel@LIGO.ORG - posted 18:51, Tuesday 22 July 2014 - last comment - 19:14, Wednesday 06 August 2014(12932)
Lonely, Forgotten GS13 at EX
J. Kissel, R. Schofield

I discovered a lonely, forgotten, disconnected GS13 hiding under BSC9 (H1 ETMX) chamber today. I attach pictures. 

Things that Robert and I can surmize:
- It's serial number is 574, and has a "property of the USGS, greater than $5k" sticker on the side with the number G12077 and a bar code.
- It may have been used for S5/S6 feed-forward studies (Will check with Mike, Keita, Richard)
- Ski may have purchased it, given the bar-code on the side (Will check with John)
- It's a 2005-ish era model, based on the color of its can and unfinished look of the feet.
- It's currently configured as a horizontal
- It claims of a broken locking mechanism, but after a few turns the mass seemed locked enough for transport
- It's functionality is unknown.

Finder's keepers ...
Non-image files attached to this report
Comments related to this report
jeffrey.kissel@LIGO.ORG - 17:09, Friday 25 July 2014 (13003)SEI
J. Kissel for R. McCarthy, M. Landry, K. Kawabe, R. Schofield, B. Lantz, and J. Giaime

Various hazy memories have added up to a conclusion: this above mentioned GS13 was part of the S5/S6 differential feed-forward work on H1. It's pair at EY is also disconnected, but is in more "formal" storage on the wire racks in the change room / air lock before the YVEA. There're actually two on that rack, I attach pictures of both. Robert believes the other is "his," i.e. purchased with PEM dollars (though does not know which is whose). Lantz and Giaime believe the non-PEM GS13s were originally purchased for LLO's PEPI prototyping.

In summary -- three GS13s, all in the horizontal configuration, serial numbers:
574     EX, under BSC9
578     EY, on cleanroom racks
584     EY, on cleanroom racks
All have custom readout cables attached, with signal readouts on a BNC and power on a 4-pin lemo.

574 claims to have a broken locking mechanism, and 578 is missing it's back, adjustable leveling foot. Interestingly, the locking knob on 584 has a groove carved out of it. Perhaps this might have been used to prototype a locking mechanism (originally a part of the aLIGO design before Stanford innovated the lock-free GS13s we have today).

And now you know... the rest of the story.
Non-image files attached to this comment
jeffrey.kissel@LIGO.ORG - 19:14, Wednesday 06 August 2014 (13252)
J. Kissel

I found *another* disconnected, unpodded GS13 sitting in the North East (+X,-Y) corner under BSC5 (H2's ETMX) chamber. His serial number is 568, and has a similar property barcode on it as the others, and it's configured as a vertical, so my guess is that each end station had an horizontal and a vertical. The EY one's are locked up, and I didn't bother checking their configuration. They're marked as "H" on the horizontal leveling feet, but that is not necessarily indicative of the configuration since they get changed and the label is oft-not updated. I attach pictures.

I locked the instrument, and brought it out the change room (similar to where S/N 578 and 584 are stored at EY).

This brings the collection up to:
S/N     Config      Current Location
568        V        EX, in change-room, by bench
574        V        CS, In my office
578        ??       EY, on change-room racks
584        ??       EY, on change-room racks
Non-image files attached to this comment
H1 PEM (SEI)
jeffrey.kissel@LIGO.ORG - posted 18:33, Tuesday 22 July 2014 (12931)
H1 Vault STS2 Removed for Repair
J. Kissel, for R. Schofield and R. McCarthy

While in the EE Lab today, I discovered an STS peaking out of the corner under some boxes. Asking around, Robert / Filiberto confirm that this STS is the H1 Vault STS that has been retrieved for the recommended repair at the beginning of the year. Robert recalls removing it from the vault on 2014-Jun-18. It will be sent out to Quanterra for repair, in due time.

The STS's serial number is 89921. 

The breakout box / satellite box that goes with the STS has been left out in the vault. 

Note: this is a PEM STS2, NOT an SEI STS2. It should be returned to the vault once repaired.
Non-image files attached to this report
H1 SEI (DetChar, PEM)
jeffrey.kissel@LIGO.ORG - posted 18:21, Tuesday 22 July 2014 (12930)
H1 EX GND STS Oriented Incorrectly
J. Kissel, H. Radkins

To investigate the H1 EX GND T240's input matrix confusion, I drove down to the end-station to check the alignment of the T240. I've found the "N" label pointing in the North direction, which for LHO is the +X direction. Seems logical. 

However, looking further into the T240's user's manual, on pg 23, section 5.2, table 5-1 (for revision 6; in revision 4 has this table on pg 14, section 4.4, table 4-1) it states 

Axis    Orientation        Positive Voltage
 X       east-west         represents motion to the east
 Y       north-south       represents motion to the north
 Z       vertical          represents upward case motion

Hence, the "N" label should be aligned parallel to the Y axis, and it is not. 

We've misplaced all of our alignment rods (STS2s and T240s alike), so Hugh's ordering some stock to make several "swizzle sticks" which have ends that fit in both instruments (see SEI aLOG 523 for dimensions of the alignment holes). Once we have an alignment rod, I'll rotate the T240 and correct the input matrix.

The attached pictures show proof of the mis-alignment:
Page 1: From a distance, looking EAST (-Y direction), with the WEST wall at my back, and BSC4 to the left; the T240 sits in its black igloo at the focal point of the picture.
Page 2: A little closer now, igloo removed, looking in the same direction (EAST, -Y).
Page 3: Even closer, but now I've rotated to look DOWN, SOUTH (-Z,-X) direction, with the +X direction and BSC4 at my back.
Page 4: And ... scene. Looking in the SOUTH / -X direction I see the "N" staring me in the face. Eureka!
Non-image files attached to this report
LHO VE
stuart.aston@LIGO.ORG - posted 17:35, Tuesday 22 July 2014 - last comment - 17:49, Tuesday 22 July 2014(12926)
Purge air turned down at 5:20pm (local)
[Arnaud P, Stuart A]

Purge air was turned off at the valves near HAM4 and HAM6 in the LVEA at 5:20pm (local) while we take measurements on the SR3 (HLTS) suspension.
Comments related to this report
stuart.aston@LIGO.ORG - 17:49, Tuesday 22 July 2014 (12927)
Purge air was restored to original valve positions at 5:45pm (local).
H1 CDS
patrick.thomas@LIGO.ORG - posted 17:32, Tuesday 22 July 2014 (12925)
updated conlog channel list
added 368 channels, removed 367 channels
The number of unmonitored channels dropped from 354 to 13. The list of unmonitored channels is attached.
Non-image files attached to this report
H1 SUS
stuart.aston@LIGO.ORG - posted 17:12, Tuesday 22 July 2014 - last comment - 08:05, Wednesday 23 July 2014(12923)
SR2 (HSTS) M1-M1 Phase 3a TFs show issue with LF BOSEM channel
Following doors being hung on the HAM4 chamber earlier today Phase 3a DTT TF measurements have been taken this afternoon for SR2 (HSTS) suspension as follows:-  

- SR2 M1-M1 undamped results (2014-07-22_1200_H1SUSSR2_M1_ALL_TFs.pdf)

HAM4 ISI Status: ISI unlocked, no damping or isolation loops running.

SR2 alignment: No offset was applied during this measurement.

SR2 undamped measurements from above have been compared with other H1 HSTS suspensions at the same Phase of testing (allhstss_2014-07-22_Phase3a_H1SR2_UnDamp_ALL_ZOOMED_TFs.pdf). The plot key is as follows:-

Blue Trace = Model (hstsopt_metal)
Orange Trace = H1 SRM M1 (2014_07_21_1400), Phase 3a (in-chamber, doors hung) 
Magenta Trace = H1 SR2 M1 (2014−05−07_1083546862), Phase 3a (in-chamber, no doors)
Cyan Trace = H1 SR2 M1 (2014−07−22_1200), Phase 3a (in-chamber, doors hung)

Summary:

It can be seen that back on May 7th SR2 M1-M1 TFs looked good (magenta trace). However, subsequently, SR2 appears to have developed an issue with the M1 LF BOSEM channel (cyan trace). This was not evident in recent TFs taken during close-out activities since there is a window of opportunity to take P and V DOFs. We next need to further investigate the actuation chain (applying offsets, measuring coil resistances etc.) to determine if the fault resides in-chamber or with the electronics.   

All data, scripts and plots have been committed to the sus svn as of this entry.
Non-image files attached to this report
Comments related to this report
stuart.aston@LIGO.ORG - 08:05, Wednesday 23 July 2014 (12938)
[Stuart A, Arnuad P, Jeff K]

We believe the SR2 M1 LF channel problem is a 'typical' actuation failure that we have seen for other suspensions, and at both sites, before (see LLO aLOG entries 12296 and 12416, as well as LHO aLOG entry 12544).
matthew.heintze@LIGO.ORG - 06:40, Wednesday 23 July 2014 (12936)

Oh man....we cant catch a break at the moment. Both HAM3 suspensions are unlocked at the moment. Can you do whatever tests yu need to do (TF's, power spectra, other) before I lock them for cleaning FC, so that we can give those a clean bill of healtth at this stage >

H1 SUS
betsy.weaver@LIGO.ORG - posted 17:00, Tuesday 22 July 2014 (12924)
ITMy SUS work continued

After HAM work subsided and we were able to get into the BSC, we worked on the ITMy reaction chain DOF alignment as well as the lower stage OSEM alignment.  More of the same tomorrow.

H1 SEI (INS, SUS)
hugh.radkins@LIGO.ORG - posted 16:29, Tuesday 22 July 2014 (12922)
WBSC1 ITMY HEPI Alignment Offsets

IAS needed a 0.2 mm shift to the North (+X) to bring the SUS into spec position.  I closed the RZ loop at the past (last few weeks while position loops were NOT closed) location(-16200nrad); then I drove the X degree 200000nm from its free hang position.  Jason was unable to see this change and it turns out that this amount of shift is barely out of the instrument resolution.  I drove it another 100um and the shift now is revealed.  The free hang position of the HEPI X Dof was -8000 so I've rounded the Bias Target to 300000.  I believe this position will satisfy IAS.

The Ry Dof was unstable so that will have to be worked out before HEPI can be unleashed completely.

H1 General
jeffrey.bartlett@LIGO.ORG - posted 15:59, Tuesday 22 July 2014 (12921)
Ops Summary
LVEA laser safe

08:35 Scott from Apollo sheet metal on site
08:38 Several surf students going to End-X for PEM testing
08:52 Darkham & Forrest – Going to End-X
08:52 Matt, Kate, Apollo – Working on SR2 and reinstalling door on HAM4
09:22 – Richard – In LVEA for survey
09:25 Travis – Pulling PCal target at End-X
09:25 Nathan – Working in the Optics lab
09:57 Scott from Apollo sheet metal on site
10:00 Arron – Working on Illuminator switch and noise eaters at End-Y
10:00 Cyrus – Fixed JRE error on control room video monitor terminal
10:20 Apollo – Pulling HAM5 south door    
10:30 Matt, Jeremy, Stuart – Going into HAM5 to check for rubbing on SR3
10:41 Karen – Going to End-Y 
10:55 Dave & Jim – Working on hardware watchdogs software at End-Y
11:05 Mike V. – Going to End-X
11:30 Apollo - HAM5 Door replaced
11:42 Paradise Water on site for delivery
13:30 Matt & Jeremy – First contact work in BSC3
13:30 Betsy & Travis – Installing BS baffle in BSC2 and working on BSC1 alignment
13:58 Jim – Balance work in BSC2
14:03 Gerardo – Going to End-X to work on PCal viewport
14:05 Doug & Jason – Alignment work on ITMY
14:15 Jeff – Tilt meter investigation at End-X
15:05 Dave – Restart PEM models to pick up name changes and then will restart the DAC
15:19 Hugh – In LVEA to work on ITMY alignment
H1 INS
jim.warner@LIGO.ORG - posted 15:24, Tuesday 22 July 2014 (12920)
BSC2 ISI unlocked, rebalanced
I went into BSC2 this afternoon and unlocked and rebalanced the ISI. I started by removing 2 kg of optical table mass in a pattern roughly evenly distributed around the SUS. I then unlocked St2 and looked at CPS's, but the level was still slightly out of spec. I then removed some side wall mass from St2 (a D071200 t1), which brought St2 into spec. I then unlocked St1, took another look at cps's, found everything happy enough, so I packed up. I left the ISI unlocked as I'm hoping to run tf's soon.
H1 PEM (DAQ)
david.barker@LIGO.ORG - posted 15:17, Tuesday 22 July 2014 (12919)
PEM model changes, DAQ restart

Robert, Christina and Dave.

Some PEM names were changed in the CS and EX models. The CS changes are to standarize channels with FLOOR in their names (e.g. FLOOR_XCRYO becomes LVEAFLOOR_XCRYO). The EX change was to fix an incorrect name  (ACC_OPLEV_ETMX_X becomes ACC_OPLEV_ETMX_Y).

the h1pemcs and h1pemex models were restarted, followed by a DAQ restart.

The DAQ restart cleared the 0x2000 errors on the ODC EX and EY models.

H1 CDS
david.barker@LIGO.ORG - posted 13:13, Tuesday 22 July 2014 (12918)
HWWD testing at EY

Jim and Dave.

After seeing some confusing trend data about what the default RMS-trip level and time-to-kill times are (should be 110mV and 20mins respectively), we went to EY and performed the following tests:

pre-test: put SUS, ISI and HEPI into safe states, no DAC drives anywhere. The IOP SWWDs for SUS and SEI were panic'ed.

1. powered down the HWWD, verified 3 ISI Coil drivers were powered down.

2. powerd up the HWWD, noted it would not boot until we pressed the front panel reset button.

3. read the HWWD settings via BIO connection to h1susetmy model's hwwd part, settings of 110mV and 20min confirmed

4. restarted the h1susetmy model, noted that the hwwd part in the model seems to program the HWWD without being asked to

5. unplugged the control BIO cable from the back of the HWWD (retaining the monitor BIO cable), restarted the h1susetmy model. Its hwwd programming part froze with lack of acknowledgements, but the LED monitoring continued to work

Lastly we plugged everything back in, un-panic'ed the IOP SWWDs, damped/aligned SUS, damped/isolated SEI.

H1 SUS
stuart.aston@LIGO.ORG - posted 12:41, Tuesday 22 July 2014 - last comment - 17:59, Tuesday 22 July 2014(12917)
SR2 and SR3 Transferfunctions Running
Manual DTT transfer functions are now running on SR2 and SR3 for the next few hours.
Comments related to this report
stuart.aston@LIGO.ORG - 17:59, Tuesday 22 July 2014 (12928)
Now complete.
H1 INS
matthew.heintze@LIGO.ORG - posted 11:56, Tuesday 22 July 2014 (12915)
HAM4 and HAM5 update

(Apollo, Kate G, Jeremy B, Stuart A, Matt H)

Quick alog. More detail to come later....or from someone else

We pulled the First contact on SR2. Optic suface still looks the same as last night in terms of not being great in terms of cleanliness (even tried blowing with top gun for 2-3 minutes after FC pulled). The decision was to go ahead and put in bug report about optic.

Particle counts were great throughout, and after unlcoking Stuart did some quick TFs and gave the all clear. ISI south side unlocked and door went on. Process went really quick and well.

 

For HAM5 Stuart had seen the most subtle suppression of the first peak of the vertical TF, so must have the ever so slightest of rubbing somewhere ( I am sure he has made an alog about this, I am too tired to search for it). Decision was made to see if could find it. So we pulled door back just enough to allow Jeremy and I to get access to the table (everything still inside the cleanroom).We put flange protection on the bottom section of the chamber just in case (better safe than sorry). Locked half the ISI, adjusted M3 OSEMs as requested and looked for rubbing. Couldnt see anything obvious. Ones I was most suspicious about was the top EQ stops of the intermediate mass on the HR side. Blade EQ stops look fine. Ive backed a few things off. Stuart ran quick TFs nd nothing definitive could be seen from the resolution. Ran a couple average higher resolution TF in vertical. Stuart seemed to be happy with what he could tell in the circumstances so door went back on. Time of door off to door on was around 50 mins (TFs took a chunk of time). We did particle counts throughout and all were low...it really seems that having people not moving about in the BSC chambers correlates with low counts in the HAMs even all the way up at HAM5). Stuart has recordings and hopefully will post.

Note: I also noticed that the nuts on the top EQ stops on the upper mass (the ones in the tablecloth) had not been engaged. With the table half unlocked like it was I wasnt able to get to them in a way to engage them, but the stops appear to be a long long way back from the upper mass, so the chances of them vibrating down to start touching I think it low....well for the two that I could see...cant see the ones on the inside of the table)

South door back on with 4 bolts and my fingers crossed that its all good.

H1 General
jeffrey.bartlett@LIGO.ORG - posted 10:37, Tuesday 22 July 2014 (12914)
08:15 Meeting Minutes
Matt and crew are working at HAM4 to remove second application of First Contact. If the optic is cleaner than yesterday the south door will be put on.

There is slight vertical rubbing on SR3. The south door will need to come off for this to be checked. When the door is off the M3 AOSEMs will also be adjusted.

Betsy & Travis working on OSEM alignment, optic alignment, and ACB install in BSC1.

Travis to remove target at End-X for PCal. The PCal group will be doing reflectivity testing at End-X.

Richard working at End-Y on cabling. 
H1 INS
matthew.heintze@LIGO.ORG - posted 22:22, Monday 21 July 2014 - last comment - 14:45, Friday 01 August 2014(12906)
Start of closing up of chambers...mixed success

(lots and lots of people)....and I want to thank ALL these people for all their help today. Everybody was willing to pitch in and help, and was fantastic that that happened.

Its been another long day and I am tired so this will be quick (more detailed report to come)....also apoogies if this alog makes no sense. My mind is mush now.

 

HAM5 was closed up today. ISI balance was rechecked and slightly altered, clean of chamber  happened, had also to pause for some time where we had to wait until particle counts dropped to level happy to peel FC off SR3 but eventually got both doors on. We did notice that when FC pulled immediately it looked awesome, and then in the time before door went on, started to see small amounts of particulate already coming back. After doing some quick TFs in a couple DOF's it was given the okay to put doors on and they were put on as quickly as we could. We did learn various things on how to speed up, etc.

Rough timeline: 1st contant removed 11.20am 1" optic. 11.44am first contact removed from SR3 optic. North door on ~12.37pm, South door on ~13.14pm.

 

Changed up the order for HAM4 door and ISI was half unlocked and North door went on before started anything (discovered after door went on that first contact is still on the inside of the viewports :-(...after discussion with Mike L we will pull off the viewports at a later date to remove). From that we had to wait an awful long time trying to wait for particle counts to drop out of the hundreds. Things learned is we found counts spike when door gets put on, couldnt have the BSC chamber cross flow on as would make counts in the hundreds in HAM4, same with people trying to work in BC1, or even lifting a cover elsewhere. Eventually counts went down and we pulled FC on SR2. Unfortunately right at the end of the pull the gas bottle ran dry on the top gun :-( :-(. And immediately looking at the SR2 optic it looked bad...as if we had never used FC. After a bit of back and forth and a round table discussion it was decided we would try to first contact again with everything its its present state. That is to try to re-spray FC using the hold on cone and if that didnt work to paint on FC after first trying blow off anything that we could. We found the cone didnt work (wouldnt fit) and so we painted. Was a pain as coulndt really see it, but we got it done in the end (well done Kate and Rich for staying behind with me to get this done..your help is appreciated more than can express). So will try to pull FC again in the morning and we will see what we see.

 

Hopefully others will make alogs regarding particle counts, etc. ...and I may try to write a more detaield report at a later date with some photos etc depending on if they turned out when look at.

Comments related to this report
calum.torrie@LIGO.ORG - 09:25, Tuesday 22 July 2014 (12912)

Following up on Matt's alog above and to expand on a few items.

Before we agreed to "try again" with FC at SR2 in HAM4 we had a round table with Calum, Matt, Jeff, Rich, Kate and Mike Landry. Based on the gas and the issue of higher counts in chamber we decided to try again. (We could left and dumped to bug list but we thought worth to try again.) As Matt mentions we discussed several options including re-doing it with bolt on cone, using handheld cone or brushing. To use bolt-on cone we would needed to have locked ISI, removed suspension stops etc ... and would have lost ~ 1 days work. So we gave team option of handheld cone or brushing. We went through details associated with brushing i.e. 1) clean with gas from top gun first prior to brushing 2) use new and many brushes 3) only brush if guys happy with visible inspection with green light prior to brushing 4) use new batch of FC which just arrived st LHO on 21st July 2014.

I should also add that regardless of what happens today they will move ahead with close i.e. if successful we will move on and if still "dirty" we will take photos then write up a bug report and move on.

Two recommendations from this (while not responsible for issue they are good lessons): -

1) During pulling etc ... one person should be on gas bottle / top gun duty and watching bottle pressure. I was doing this while present but didn't do a great job re-assigning it i.e. I asked Matt to re-assign rather than doing it myself. (Betsy had got 2x bottles re-filled as well so they were available.)

2) Colored or different bottles for 1:1 mix versus cleaning mix or other. Why? Later (at 4am) I remembered that Kate and I had observed that the FC spray on SR2 looked different and that particle count had been low. I wonder if I grabbed the wrong bottle from the table and perhaps sprayed with a mixture that had more thinner than polymer? This has since turned out not to be the case as was reminded we pump before use to check consistency. (Should also mention we do label bottles with mix date, mixer and exp date.) Still worth a look though on colored or different bottles.

PLEASE LOOK OUT FOR FULL ALOG ON THIS FROM KATE.

stuart.aston@LIGO.ORG - 12:35, Tuesday 22 July 2014 (12916)
Attached below is a log of particle counts taken during the HAM4 work covering the duration 1415 to 1620 (local).
Non-image files attached to this comment
matthew.heintze@LIGO.ORG - 18:52, Wednesday 23 July 2014 (12959)

Celebrating SR2 being repainted and what an epic work week its been

Images attached to this comment
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