Changed CP4's level PID setpoint to 75% full (down from nominal 92%)

I'll put in a Work Permit tomorrow that details the process of letting CP4 go "dry".  Starting from 75% full will give a little head start to the lengthly process.  Chandra R. has lots of activities related to CP4's decommissioning scheduled for this week so we don't have a lot of "wiggle room".  


This step may well result in CP4 level alarms tonight.  This is expected and is being monitored remotely. 

Aborting low temp bake-out of CP4 Turbo+RGA

Having started 4 days later than originally planned combined with a (Kyle-typical) too conservative rate-of-rise (40C after 24 hrs.), I've decided to abort the low temperature bake exercise.  I had hopped to soak at 65C - 80C for a few days to see how the current iteration of heated zones (flexible heat wrap) behaved and also to dry out the wet fittings a little.  Though the individual components had been Class-Ad initially and redundantly vacuum baked after assembly, an unforeseen reconfiguration was needed that required venting the turbo+RGA assembly with "room air".  Additionally, the 10" gate valve (O-ring sealed) at CP4 was also exposed to wet air to facilitate the installation.  So, getting a useful "before" scan of CP4 would require some form of bake.  No worries.  A "before" scan would be interesting (but optional).  What will really matter is getting a sensitive "after" CP4 bake scan prior to combining it to the rest of the site.  This won't be a problem as we will have lots of time and the setup is now done.  

Notes:  
As found today, the turbo inlet pressure was 2.0 x 10-7 mbar while at 40C.  Also, the scroll pump seemed way too warm for not having a gas load.  Hmmm.....foreline leak? I didn't have a gauge on the foreline initially so I installed one today.  It showed 8.5 x 10-3 torr on the Tee at the scroll inlet which is ~7 ft. away from the turbo exhaust and 10 minutes after pumping the foreline back down.  Still, it isn't typical to run so warm without pumping gas.  For now, I setup a fan to cool the scroll.  

On site working solo.

I'll be at Y-mid VEA making temperature measurements and/or adjustments or in the VPW tinkering with VBOC.  I expect to only be here 90 minutes or so.  Gerardo M. is my "phone buddy" and I'll make a comment to this entry when I am leaving the site. 

1603 hrs. local - Kyle leaving site now.

PSL is off

I came in to do some last DRMI/PRMI tests, and found the laser is off.  This happened about 4:15 am pacific time.  THe epics channels don't show any problems with the chillers, and it looks like the power watch dog tripped after the laser went off. (screenshot attached)

Various data trends are attached.  At the time the power watchdog was engaged the output power was ~34.8 W.
There is no indication that the power decreased by 15% since the watchdog was enabled.  Trend data also
suggests that the amplifier dropped out before the NPRO.

Indeed the front end laser was tripped off by the power watchdog.  The trigger signal for the watchdog is the output of the third
amplifier stage and not the output of the front end - something that is rectified with the upcoming front end laser modifications.
When the watchdog was last engaged the power was ~106.  The watchdog tripped in at ~90, ie at the 15% drop level.  So the watchdog
worked as it should.

    Oh and the drop in power is most likely due to the large drop in relative humidity.  We know the e-beam sputtered coatings
for the pick-offs have issues with relative humidity.

Kyle on site

I plan to make a check of the (3) turbo pumps in the LVEA as well as the LVEA purge-air supply (a.k.a. the "Kobelco") in the Mechanical Room.  Following that, I'll be back and forth between the VPW (tweeking VBOC) and the Y-mid VEA doing work related to WP#7335.  I won't be operating pwr tools, using the crane or climbing on ladders.  Gerardo M. is my "phone buddy" and is aware that I am here and what I'm doing.  I'll text him at 3 pm or whenever I leave whichever comes first.  I'll also make a comment to this log entry when I leave.  

Baking of turbo+RGA components at CP4's 10" valve was started at around 1530 hrs. local time.  I'll need to come back tomorrow morning and again tomorrow evening to make adjustments.  I expect PT245 to increase as a response to the adjacent warming parts but have no idea what to expect as to rate of rise or peak value.  I also can't remember what the alarm set point for PT245 is currently set to.  So, we may get an alarm at some point.  

~1700 hrs. local -> Kyle leaving site now.

ISCT6 green path faraday isolator measurement

Terry, Nutsinee

Got some measurement of the EOT faraday isolator on the green path:

Over all transmission ~ 91% (S and P pol)

• 91% S-pol went through
• 91% P-pol rejected
• ~9% loss

Isolation ~ -26dB

Couldn't find a non-polarizing beam splitter for 532 so I used a dichroic beam splitter set at weird angle (~30 degree or so) to partially let light though. I used one of the precision photonics mirror found in the SQZ bay drawer to reflect transmitted light straight back into the faraday and measure the light that bounced back from the beam splitter. I couldn't measure the part of back reflected light that went though the beam splitter so I guesstimated the transmission knowing what came in and what gets transmitted on its way into the faraday. Terry thinks this number is disappointingly low, given the dodgy set up I'd take this number as an upper limit (in a sense that it can't get any worse). But again, given the nearly 10% loss maybe we just have a not-so-great isolator. 

measuring spot positions in PRC

This afternoon Georgia and I locked PRMI and ran a2l for PRM, PR2, and PR3.  

	PRM	PR2	PR3
P2L	1.099	0.173	2.614
Y2L	0.046	-8.34	-0.050

There is a file called by the a2l scripts (for the matrices) that is no longer in the place it used to be.  We added the ads matrix to the list of matrices used in ISC_library, so that these scripts now import and use that.  

ETMy status update

Another round of alignment, rubbing checks, TFs, rinse, repeat were done today.  We got to the reaction chain positioned in approximately the right location with respect to the main chain in the longitudinal direction and the pitch close enough that the inter-chain bump stops are approximately equidistant.  We decided to stop at this point to run some TFs, which, of course, showed some issues.  We eventually got the main chain free of rubbing and took a full suite of low resolution TFs, enough to tell us that we are healthy and free-swinging.  

For next Monday, we have on the docket to do some cable and ESD checkouts with EE and take a set of fully suspended violin mode measurements.  Then on to fine alignment of both chains.

Shift Summary - Day

TITLE: 02/09 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC

STATE of H1: Planned Engineering

INCOMING OPERATOR: None

LOG:

15:52 (7:52) Bubba, guest to LVEA, Vertex

16:00 (8:00) Start of shift

16:16 (8:16) Hugh to LVEA

16:16 (8:16) Bubba, guest out of LVEA

16:23 (8:23) Hugh out of LVEA

17:15 (9:15) Peter to LVEA

17:19 (9:19) Peter out of LVEA

17:24 (9:24) Corey to Optics Lab -- Pick up parts

17:24 (9:24) Karen to Mid-Y

17:33 (9:33) Corey to LVEA -- Deliver parts

17:50 (9:50) Peter, Phil to End-Y, End-X -- Access control installation

18:05 (10:05) Karen leaving Mid-Y

18:06 (10:06) Corey back from LVEA

18:23 (10:23) Travis to End-Y

18:26 (10:26) Terry to SQZ Bay -- Place optics, label cables

18:26 (10:26) Sheila, Georgia to HAM6

18:37 (10:37) Richard, Phil, Peter to End-X

18:40 (10:40) Nutsinee to SQZ Bay

18:40 (10:40) Travis back from End-Y, going to Optics Lab

18:49 (10:49) Mark to Mid-Y

18:56 (10:56) Mark to CER -- Sticker delivery

19:00 (11:00) Mark back from CER

19:01 (11:01) Jason to LVEA -- Grab cart

19:12 (11:12) Jason out of LVEA

19:13 (11:13) Mark back from Mid-Y

19:14 (11:14) Richard back from End-X

19:50 (11:50) Jason to PSL enclosure -- Delivering equipment

19:57 (11:57) Jason back from PSL enclosure

20:10 (12:10) Evan to Electronics Bay -- Take photos

20:11 (12:11) Nutsinee out of SQZ Bay

20:15 (12:15) Evan back from Electronics Bay

20:42 (12:42) Corey back from Optics Lab

20:47 (12:47) Nutsinee to SQZ Bay

20:53 (12:53) Elizabeth to End-X -- Installing network switch

21:07 (13:07) Hugh to Optics Lab

21:10 (13:10) Betsy and Travis to End-Y -- ETMY work

21:19 (13:19) Elizabeth back from End-X

21:32 (13:32) Mark to Mid-X

21:52 (13:52) Nutsinee back from SQZ Bay

23:12 (15:12) Hugh to LVEA

23:35 (15:35) Ken back from Mid-X

23:49 (15:49) Travis and Betsy back from End-Y

23:59 (15:59) Hugh out of LVEA

00:00 (16:00) End of shift

118/72 MHz RF Distribution Chain

Marc, Daniel

We installed the RF multipliers and the RF distribution amplifiers for the the 118.3 MHz (13^th harmonics) and 72.8 MHz (8^th harmonics) signal chains. The entire RF distribution chain now shows green. There is still a temporary 2W amplifier mounted at the bottom of ISC-C4 to drive the EOM.

Checked clearances in HAM6, needs a little more work tomorrow

[Georgia, Jenne]

With the new alignment after the arm peek and the locking of DRMI, we popped in to HAM6 to confirm that all of the clearances are okay, and the beam is well centered on all of the in-vac optics.  Summary: we need a dog clamp (email already out to Corey to grab us some), and a teeny bit more work tomorrow, then we're done.

* Clearances seem good, although it would be good for another set of eyes to have a look at the shutter-closed wire clearance. 

* We were a bit high on the last steering mirror and the lens in front of AS_C, so Georgia centered us up using the steering mirrors closer to the OM1 transmission point.

* We need to re-look at the AS WFS path. We're a little too close to the edge of the first mirror in transmission of OM3, but can't move the mirror appropriately until we have another dog clamp.  Right now it's got one dog, and one bolt in a hole.  But, we need to move another mm or so, and then won't be able to use the bolt hole.  We're a little close in range on the steering mirror in front of AS_B, so we might also relieve some of that with the upstream mirrors while we're in chamber tomorrow. Also, the beam isn't centered well enough on the BS that splits the 2 WFS beams, or on the lens in front of that BS. So, basically the whole AS WFS path needs attention, but the first thing is that first mirror that needs a new dog clamp.

* There is a connection on the fast shutter that seems like it might be loose.  Georgia will post a photo in a comment to this alog.  We should make sure this is fully seated.

DRMI locking

Jenne, Georgia, Sheila

After yesterday's peak down the X arm, we worked on locking the vertex with our ITMX and input beam pointing set by the X arm. 

We started with locking PRX+PRY, this worked fine, the refl spot is low and to the left on the REFL camera.  We had to make some guardian adjustments throughout the day in places where we were using ASAIR sensors.

With PRX+PRY locked, we walked the RM alignments until they were close enough that we could turn on the REFL WFS centering loops.

We aligned MICH by moving ITMY, then later adjusted the beam splitter.  We were able to lock MICH using the ASC_AS_B_RF45 sum, to do so we needed to flip the sign.  We also reduced the gain setting by a factor of 2.

We locked PRMI without any problems, and adjusted the alignment by hand.

We then set the SR3 alignment for the new beam by feeding AS_C centering back to SR2 and moving SR3 until we started to loose power on AS_C_SUM.  We set SR2 to center on AS_C, and searched for the SRM alignment that gave us SRY flashes.  We were able to lock SRY using the new AS45 sensor, with a sign flip and no gain adjustment.

We locked DRMI, the only things that were different from the guardian default settings was that we reduced the MICH trigger from 20 to 7, and we have 3.3W into the IMC. We weren't able to turn on ASC but we will come back to that tomorrow.