ETMX PCAL baffle progress

This morning Corey, Niko and I went to EX and installed most of the remaining PCAL baffle pieces. We looked over the panels, top-gunned them, then I went inside and Corey and Niko handed the pieces to me from the door.  After putting the pieces on, I tried to get a couple of picture of the install and any particulate. First attached image is a view of the installed panels from approximately the the aperture of the arm cavity baffle. 

The barrel baffle pieces were installed a couple weeks ago, and the lower panel has been accumulating particulate, second image. I was pretty easily able to wipe away the fuzzies with a dry wipe, but the barrel panel immediately started accumulating again (third image is the lower panel piece after wiping). Before I left, I did not notice any increased particulate on the front baffle pieces we installed today.  Travis noted before we closed ETMY (the first time?) that the panels on that PCAL had also accumulated some particulate, so it seems we will have to consider adding a wipe down step for the baffles to chamber close out.

Black nickel barrel baffle panels + dry wiping is likely to contribute static charging, which may accelerate the rate at which particulate makes its way onto these panels - we should revisit this in discussion with SYS, perhaps via the "Updated procedures for handling the coated baffles" email thread. 

assembled first LHO IP chevron baffle

Stephen A., Chandra R.

This morning Stephen helped/instructed me on assembly of the first LHO chevron baffle. Baffle SN 001 was installed in nipple housing SN 001. We iterated several times on bending the louvers to securely set them in place and ended with an N2 "top gun" blow off before bolting the two baffle halves together and fastening to the nipple housing. The eight bolts that secure the baffle to the housing still need to be torqued. We placed the two 16.5" Cu gaskets on knife edges and wrapped with Al foil for temporary storage in VPW until we can install on IP11 at EY later this week. Stephen will post pictures later.

Refer to LLO aLOG for more detail on steps of installation. https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=38375

Shift Summary - Day

Morning subbing for Niko while he does some PCal work:

14:40 Jeff B ou to LVE to remove house vacuum system

 14:53 M² installing platform at HAM6

15:47 Norco on site with LN2 delivery - xxxxx75

15:50 Marc out to LVEA  - PSL & HAM6 rack area

15:55 Richard ou to LVEA

15:45 Peter and Carlos out to PSL to replace a computer in the enclosure

15:56 Hugh out to HAM6

16:00 Travis out to EX

16:21 Richard out to LVEA

16:27 Richard out

16:38 Karen to EY ad then MY

16:45 Cintas on site

16:47 Nutsinee out to Squeezer table to retrieve serial number

16:50 Peter and Carlos out

16:52 N back

16:53 Betsy, Slawek and Sebastian out to EY

17:13 Carlos out to LVEA - PSL area

17:15 Terry out to Squezer table

17:21 Terry back

17:22 Betsy back and out to EX.

17:23 LVEA is LASER HAZARD

17:27 Paradise Water on site

17:30 TJ out to HAM6 to work with Hugh

17:37 Carlos out

17:49 Karen leaving EY for CS

18:04 Fil back

18:09 Hugh back

18:10 Niko back

PSL Weekly Report - 10 Day Trends FAMIS #6193

70W installation - ongoing

Rusted sprinkler pipe at LSB

A very rusty (nearly all the way through) sprinkler pipe was discovered in the LSB interstitial yesterday. The pipe had a very minor leak where the down leg screws into the 90 degree ell and finally formed enough rust and calcium deposits that started deteriorating the pipe from the outside in. I have isolated the system and will replace the pipe. 

I have also filed an FRS and will also input this into the FAMIS system for quarterly checks of the entire system. 

Until the pipe is replaced, hopefully today, the LSB will be without automated fire protection, all pull stations will still alert the fire department. 

70 W amplifier update

In trying to improve the mode matching into the pre-modecleaner, the alignment through the mode matching
lenses was redone because of a mechanical interference issue with already installed mounts.  With the
lenses in their calculated positions, the beam was still too big for the pre-modecleaner and the visibility
was ~40%.  More beam propagation measurements were taken to check the results from the previous week.
Re-doing the fit and allowing large variations in the amplifier output waist and location, resulted in new
positions for the lenses.  That improved the pre-modecleaner visibility to ~75%.

    At the moment, both the pre-modecleaner and reference cavity are locked but are by no means tweaked up.
I had hoped to be at this stage with less than 10 hours on the amplifier's clock but the alignment and
beam size checks took longer than expected.




 Volker Quetschke / Peter

XBM turbo valve replaced

Kyle, Chandra

I think we set a new record for valve replacement. Replaced 10" valve today at X-beam manifold turbo station. Will leak check turbo side tomorrow and beam tube side after IP6 valve is replaced and XBM pumped back down later this week.

We had to cut away some of the vinyl floor around the turbo station framing in order to slide it around on concrete.

ETMX Fiber Welding status

Angus (GLA) and Stephen (CIT) arrived this week to help with a few projects.  This morning, Angus, Travis and I pulled the FC on the ETMX AR which we applied last Fri, and then used the ergo arm to install it into the lower structure.  Stephen helped Jason set up the IAS equipment and then we spent the afternoon setting the structure, UIM, PUM, and test mass level and pointing nominally wrt each other.

Angus and Travis canned fibers in the pulling lab and brought them to EX. 

We anticipate starting the fiber welding tomorrow.

Shift Summary - Day

TITLE: 03/26 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC

STATE of H1: Planned Engineering

INCOMING OPERATOR: None

 

LOG:

 

14:00 (7:00) Peter to PSL Enclosure

14:10 (7:10) Karen to EY

14:28 (7:28) Marc, Mark, and Tyler to EY -- moving cleanroom

14:36 (7:36) Vanessa to EX

15:00 (8:00) Start of shift

15:08 (8:08) Terry to ISCT6 -- taking picture

16:35 (9:35) Mark, Mark, and Tyler to EX to grab tools, then EY to remove BSC door

16:37 (9:37) Volker to PSL enclosure

16:39 (9:39) Karen to EY

16:52 (9:52) Karen to MY

16:52 (9:52) Travis, Betsy to EX

16:54 (9:54) Chris, Jason to EX -- delivering fiber welding equipment

17:00 (10:00) Hugh to HAM6 -- CPS AND pull through

17:03 (10:03) Bartlett to Optics Lab -- reset dust monitors and update comptroller

17:17 (10:17) Richard to PSL enclosure -- dropping off equipment

17:36 (10:36) Chandra to LVEA -- work XBL manifold turbo

17:46 (10:46) Jim to EX, EY -- grab stool at EX, bring to EY

17:59 (10:59) Bartlett to LVEA -- take out in-house vacuum system

18:01 (11:01) Stephen, Jason to EX -- fiber welding work

18:09 (11:09) Corey to LVEA -- mark table panels for drilling

18:11 (11:11) Karen leaving MY

18:16 (11:16) Jim back from End stations

18:29 (11:29) Fil and Dave to CER -- examine PSL rack

18:32 (11:32) Marc to PSL enclosure, inspect chassis

18:37 (11:37) TVo, guests out from LVEA

18:38 (11:38) Peter, Volker out from PSL enclosure

18:44 (11:44) Marc out of PSL enclosure

18:47 (11:47) Dave back from CER

18:47 (11:47) Fil to LVEA

18:48 (11:48) Corey back from LVEA

19:16 (12:16) Bartlett out of LVEA

19:19 (12:19) Hugh out of LVEA

19:36 (12:36) Hanford notification, monthly siren tests occuring now until around 2:30

19:45 (12:45) Jim to EY

20:09 (13:09) Peter and Volker to PSL enclosure

20:16 (13:16) Kyle to LVEA

20:54 (13:54) Hugh to HAM6 -- work on CPS noise

21:23 (14:23) Travis, Betsy, Stephen, Angus, Jason to EX

21:33 (14:33) Mark to LVEA -- measurement at HAM6

21:50 (14:50) Mark out of LVEA

22:16 (15:16) Hugh out of LVEA

23:00 (16:00) End of shift

OPO phase matching in air

On Friday Terry and I adjusted the crystal position in the OPO to get phase matching and co-resonance at the same temperature. The take away messages are that the crystal translation stage is working and if we correct for mode matching the OPO threshold is between 7.4-8mW, and our phases matching temperature setting in air is just below 34C, both of these are consistent with our expectations.

Details:
We followed the procedure on page 215 of P1300006.  The main idea is to use the crystal temperature at which red and green co-resonante as a reference for crystal position, since both the position of the cavity axis along the wedge and the crystal temperature set the co-resonance.  There are a few caveats to the way we did this:

• The green power in the cavity was different by about 10% between some of these locks, so this is equivalent to about a 10% uncertainty on our measurement of nonlinear gain (if we had kept the green circulating power constant).
• It was difficult to set the co-resonance precisely because of the large noise on the cavity with the ISI locked and the purge air on. We were able to set the crystal position to within about 40 clicks on the translation stage driver.  We found that about 140 clicks are needed to compensate for the dispersion from a temperature change of 0.3C, so all of our temperature settings should be considered accurate to within about 0.1C as a reference for crystal position.
• We measure nonlinear gain by injecting a seed beam, scanning the seed phase, and measuring the de-amplification and amplification of the seed.  (x=(sqrt(max./min)-1)./(1+sqrt(max./min)); gain=1./(1-x).^2;)  In this case we were measuring small changes in the minimum seed power, and not with much accuracy.  This is why in addition to plotting the nonlinear gain, I've also plotted the maximum seed measured on the diode (uncalibrated).  This looks much more like the sinc function we are expecting. 

These caveats can explain why this measurement has large scatter.  We did this measurement with about 6mW of green injected into the OPO, and we saw our best nonlinear gain between 15-20 for this input power.  We can do a better measurement of the OPO threshold by changing the input power at a single crystal position, but this data gives us an estimate of the threshold as between 10 and 11 mW without correcting for our mode mismatch, and between 7.4-8mW correcting for the 74% mode matching from alog 40594. 

The LLO OPO was expected to have a threshold of 45mW with an input coupler that is 87.5% reflective for 532nm, while our input coupler has a reflectivity of 98%.  The threshold power is proportional to the green cavity decay rate, so our expected threshold for this OPO is 7mW (45mW*(1-sqrt(0.875)/(1-sqrt(0.98)). 

Terry and I left the crystal at the position where we see co-resonance for 33.75C, because we think this is about at the peak of the phase matching curve.  This procedure will have to be repeated once HAM6 is pumped down.

 

Update Port Speed for Optics Lab Dust Monitors

   Jeff B., Dave B.

   This morning the port speeds for the dust monitors in the Optics Lab (LAB1 and LAB2) where updated to 19200. Port #4 on the Comptrol was also updated to 19200. The Comptrol was power cycled as was the weather station. Dave B. restarted the weather station model and burt restored the alarm levels. 

   This completes the site dust monitor port speed synchronization. Closing WP #7439    

Add Diode Room and Optics Lab to Dust Monitor Checks

   This morning add the Diode Room dust monitor (DR1) and the dust monitors in the Optics Lab (LAB1 and LAB2) to the check_dust_monitors_are_working script. 

Monday Vent Meeting Minutes

• PSL ongoing, light by end of week
• AMD work at EY Tue-Thurs
• Replace PCal barrel baffle washers/alignment check Friday
• EX baffle installation/cleaning Tuesday onward
• HAM6 in chamber work deferred past Monday
• Swapping out ion pump valves, 10-inch valves today through next week
• Taking down fire suppression system at LSB temporarily
• In-house vacuum removal

Now what's with the low frequency Corner3 CPS Spectra on WHAM6?

See the attached...Why is the spectra below 5 & 8 hz elevated for Corner3 H & V on the CPS?  V3 is a new CPS but it has been on the shelf for years now and while it has the copper braid in place, that braid is not zip tied at the sensor end (shouldn't impact things); both are attached to a feedthru that has recently been removed and replaced several times and the feedthru is currently not torqued down (should not impact the grounding); the Satellite box was moved around and its ground lug to the house ground was exercised as the ground cable had come loose...  Need a little more attention here:

We'll try, 1) confirm ground is good on the rack put it back where it should be located under the Chamber, 2) Torque down the feedthru--like to do this after things look good but maybe it is to blame (I doubt it.)

ETMX main chain preps for fiber welding

After yesterday's gutting of the ETMX lower QUAD to remove ETM08 and it's fibers from the suspension, today we prepped to put the new ETM13 in.  Travis finished the messy work of filing off the ear horns to the appropriate lengths, and then we cleaned the PUM mass and structure thoroughly with wipes and vacuuming.  We prepped the ergo arm for another optic pickup, and then opened the ETM13 transport cake tin container.  Upon inspection, we saw ~6 quite large pieces of something on the optic face that was up (AR), so we decided to do a cleaning before picking it up with the ergo suction.  Blowing with N2 didn't seem to budge the particulate, so we applied a pour-on First Contact sheet to now dry over over the next few hours.  We'll resume installing the optic into the lower structure on Monday morning.

Travis also took the empty structure opportunity to install the NMBDs (non-magnetic blade dampers) on the UIM in this main chain structure.

squeezer beam is not found yet...

Terry, Sheila, Arijit, TJ, 

Today we made one more attempt to get the beam from the OPO aligned into HAM5 and out to HAM6, but we haven't found the beam.  

Keita loaned us a Nikon D7100 which was much better for getting a clear picture of what we were looking at than the viewer we were using yesterday.  Photos will be attached to this alog latter.

FIl also  cabled the HAM5 illuminator up to the new beckhoff controls, so we could turn that on and off.  

We started out by manually aligning the beam again through the apertures, doing a little bit more careful job this time by using the viewer to identify the edges of teh aperature and center the beam half way.  We can still see the beam hitting ZM2 through the HAM5 viewport.  We were also able to sometimes see the beam coming out the HAM5 viewport (perhaps going under the fly-offf mirror on the OFI), but latter this afternoon we weren't able to repeat that.  We were never able to see a beam in HAM6.  

We are leaving the OPO locked and generating a beam (we again have two soft door covers with a small gap to let the beam out).  We have ZM1+ZM2 scanning with an amplitude of 10,000 counts for both pitch and yaw, and SRM scanning 1000 urad.  

If this does not work, we may wait for a beam from the PSL to become available and try to see the rejected scatter from the OFI polarizer in the path towards the squeezer. 

 

CP bake enclosure installation

Per request, pictures attached of the cryopump bake enclosure installation. The installation took two days and several modifications were made before and after the bake commenced in an effort to create more uniform heat zones within the enclosure because the bottom is not achieving target temp. Modifications include:

• Changed unitrut framing at 10" valve area to make more space for turbo pump assembly, which is pumping during the entire bake process
• Added rockwool insulation in several areas to fill in gappy joints around the 4" thick insulation panels
• Reduced flow rate of recirculating air by adding restrictor plate on 20" return duct diameter in an effort to equalize heat zones within enclosure. Turns out we had a faulty thermocouple which skewed results; retained design flow rate of 2000 cfm to make up for leaks at velcro insulation joints
• Installed 10 kW heater in series to supplement 20 kW control heater which ran at 100% to achieve temperatures above 100C (target temp is 130C)
• Laid 1-2" thick ceramic sheets on top of enclosure to reduce thermal leaks
• Lined "crawl space" below enclosure floor with 2" foam board to retain heat at bottom, with option to plumb in 5 kW space heater
• Activated GN2 regeneration heating system; it ran flawlessly for over a week and then developed some kind of electrical short that we haven't been able to chase down. Flowing hot GN2 through the CP reservoir would help achieve target temperatures and prevent cold spots, but will unlikely be fixed in a timely manner

Improvements for future designs:

• We read out thermocouples in five areas (some air, some metal), but in the future would add more sensors
• The supply air exists into the enclosure directly above the return duct. We could improve heat distribution by supplying hot air from bottom and placing return duct on opposite side of enclosure
• The velcro serves as a good hold for insulation panel installation, but does not ensure that the panels butt up next to each other. Wire tie reinforcement would help bridge gaps where the thin velcro flaps fail to provide thermal barriers
• Install variable speed drive on fan

ZM1 Update: Possibly narrowing down where the issue is

This morning I got a little bit of time to try some more debugging of ZM1. Jeff Kissel's last alog (lhoalog41034) showed a big feature in the Y to Y measurement and a possible issue with the LL flag/magnet. After team SEI was done with their work and locked up the table, Corey and I checked all around the the suspension for anything that might look or feel wrong. I looked all around the LL OSEM for anything that might cause a problem but didn't find anything. I recentered the OSEMs on  their flags and then we ran the measurements again. No change.

During a lunchtime talk with Betsy, she suggested that I try to run the Y to Y measurement with the top OSEMs backed out and not actuating, and then do the same with the bottom. When I tried it, it looked like the lower frequency feature was much smaller when the top OSEMs were backed out (see attached). I got excited and tried this for pitch as well, but didn't notice much of a difference. This ended my day in HAM6 as I had other teams nipping at my heels.

These templates have been moved to 
    /ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/ZM1/SAGM1/Data/
        2018-03-19_2144_H1SUSZM1_M1_WhiteNoise_Y_0p01to50Hz_bottomosemsout.xml
        2018-03-19_2144_H1SUSZM1_M1_WhiteNoise_Y_0p01to50Hz_rightosemsout.xml
        2018-03-19_2144_H1SUSZM1_M1_WhiteNoise_Y_0p01to50Hz_toposemsout.xml