X-end on turbo

Note:  The measured dewpoint of the blow down air, i.e. the air comming out of the +1 psig VE, was -6C while the air sourced from the purge air header measured the normal <-54C.  Prior to valving-in the pumps to a vented volume I typically close the vent valve to the VE and measure the air sourced from the purge air header then close-off the header air and open and measure the air blowing out of the slightly pressurized VE.  Normally the two measure the same as you would expect and are "off scale" dry.  In this case, the two were much different.  I repeated this measurement a few times and the values were exactly repeatable.  I conferred with John W. and decided to begin pumping the "wet" VE anyway.  

The ambient humidity is high today.  I intend to investigate with the people involved with today's unlocking if they had closed-off the purge air during the in-chamber activity for some reason or if they had blocked off 1/2 of the door opening as is the norm.  Not doing so would negate the effectiveness of the purge air's ability at keeping wet room air from mixing with the chamber interior air and might explain this observation. 

I opened GV7 too.  

The mid stations don't have their pressure gauges cabled and CDS indicated values are bogus.  Y-mid seems slow to change and is still indicating ~8 x 10-8 torr at the turbo inlet.  

Ops Shift Summary

H1 ETMX was unlocked
HEPI welding continues
HAM 7 HEPI install work
assembly of test stand cleanroom
CDS work on electronics racks in LVEA for H2 ITM cartridge install

Problem with test stand M0 and R0 SD OSEM sensor channels

Since the test stand upgrade, the side OSEM sensor channels (X1:SUS-QUAD_M0_OSEMINF_SD_IN1 and X1:SUS-QUAD_R0_OSEMINF_SD_IN1) have been very noisy, to the point where enabling the SD DOF control loops would trip the watchdog because of HF signals amplified by the upward slope in the software output filter.

The noise looked vaguely digital in dataviewer but it was hard to tell due to the poor time resolution, and until today we hadn't probed in more detail. However doing a triggered time response measurement in DTT revealed that an otherwise plausible looking signal is being chopped by a rectangular window at 16 Hz with a 1/8 duty cycle (i.e., 1/128 s on out of 1/16 s). See the attached plot, which shows X1:SUS-QUAD_R0_OSEMINF_SD_IN1 (which exhibits the problem) against X1:SUS-QUAD_R0_OSEMINF_F1_IN1 (which doesn't).

HAM 7 HEPI Install

The North end of HAM 7 has had the weldments and crossbeam attached. It was a very tight fit to move the crossbeam between the two chambers. Some creativity was called for, but installing the crossbeam for HAM 8 may require even more. The next steps will be to finish the clamp on the crossbeam and torque the bolts all of the bolts.

HEPI Phase2 Welding In Progress

The HEPI Plumbing is now in the LVEA.

Image1 is the turns up on the Mezzinine.  #2 is below the mezzinine heading into the LVEA.  #3 is in the LVEA at the piping bridge.

Two Stages Floating - Testing Starts

The two stages of the first BSC-ISI have been released and balanced. 

Stage 2 total mass is 235 lb under the 6240 lb nominal. So we'll use 550 lb of mass on the keel mass instead of 785 lb. I am going to communicate the number to SYS so they can adjust their models and balancing.

Stage 1 is 135 lb under nominal (out of 8250 lb total on the large blades), about -45lbs/corner, which is very good.

Thanks to all the team for all the efforts to make it possible to float the platform only 5 weeks after we started the assembly.

We now start the testing of Unit #1, and keep working on the assembly of Unit #2. 

Ops Day Shift Summary

EX (BSC9) was prepared for door removal and unlocking of the ETM tomorrow morning.
Work at EY to prepare for receipt of BSC6.
Vacuum prep room of OSB is getting some ridiculously high dust counts. Kyle speculates that it could be air flow issues, and notes potential changes to the exhaust fan in that room.
Construction of a tall clean room in the LVEA got as far as an unadorned structure today, waiting for a ceiling, electrical appliances, curtains, etc.

Closed GV10, Vented X-end

X-mid on IP10 (10-8 torr from turbo)

Burped GV15 gate annulus into aux. cart, cracked GV15 to pump X2 hydrogen while X-end isolated.

Vertex & HAM6 pumping

LHO SUS Test Stand

Power Spectrum of LHO SUS Test Stand without any OSEMs. Disconnect at the point where octopus cables would attach. 

Interesting harmonic of interest at 16 Hz in side channel.

AC power harmonic in all channels (60 Hz)

Single Arm ISI Install

Sam and I, with much help from Richard, Filiberto, and Carl, have populated the two racks for the Single Arm Installation.  For the corner, the chassis are in, and the internal wiring is all hooked up.  At the end, most of the chassis are in, but Rolf is using the IO Chassis, and two binary chassis for some testing in the computer room, so those parts are not yet installed.  All of the cables are, at least, attached at one end, waiting for the IO chassis, or Binary chassis.  We just finished making the field cables that we need to test, and we will start testing this morning.
-Ben   

BSC Assembly Work

(Corey, Eric, Fabrice, Greg, Jim, Mitch, Sebestian)

BSCISI#1

All Sensors have been installed (that's for Stage 0->1 & 1->2).

The Trillium seismometers were received from LLO today, and were installed.  Additionally, the L4C's have also been installed.  We are currently waiting for cabling rushed from Caltech, so we can start hooking up everything and begin taking a look at the system.

Have been staging weights for loading the system, with the hopes of floating soon.

BSCISI#2

Helicoiling of the Optics Table was completed yesterday (kudos to Greg & Jeff G who did most of it--hopefully they didn't sacrifice their sanity with the task).  During this work the Jeff & Greg have come across some Q-tips which been broken off and stuck in Optics Table holes (basically, the Q-tips look like they were broken off and left in the holes---these Q-tips were wooden.  See attached photo).  A total of seven broken Q-tips were found.  (between Q-tips, moths, and aluminum oxide, the war against particles is daunting)

Continue to stage for this assembly and kit/gather all the parts needed.

Mid stations

Y-mid 8e-8 torr at turbo inlet -> leaving on MTP.  X-mid 1e-8 torr at turbo inlet -> isolated turbo and valved-in IP10.  Valved MTP back in a few hours later to check pressure since no other gauge is connected then valved-out MTP.  

Vented Vertex and HAM6

Ops Day Summary

• Racks moved inside LVEA by Y-arm
• KingSoft water checking RO system
• HAM2 door was removed, Keita and Matt entered chamber and adjusted EQ stops on MMT2
• H2adcumy had gone out of sync, rebooted and restarted it

Optical Lever long-term stability tests (Mid-y)

(Gregorio Téllez, Gerardo Moreno, Rick Savage)
 
  This week, the Optical Lever long-term stability test began with the transportation of the transmitter (TX) pylon to the Y-mid-station. The receiver-leaner(RX) pylon was in the Mid-y receiving area, but needed to be brought out of its crate and craned to the other side of the beam tube where said tests will be performed. On Tuesday, I received my access card after undergoing laser safety training. Afterwards, I left to mid-y to check on the status of the pylons and moved the laser to the other side of the beam tube together with the other items. During that afternoon, the Apollo crew at mid-y placed both pylons in the desired locations (north side of mid-y). Furthermore, during the morning meeting on Wednesday I briefed Michael Landry about the status of the installation. Later, I went to Mid-y and placed some 'Caution' tape around the area of the pylons and base plate. Some measurements were made to determine possible locations for drilling and grouting. Discussion of the findings and chosen locations will be discussed with the Caltech group and, per M. Landry, inspection of the area will be performed to confirm that the chosen locations are feasible and do not interfere with other on-going labor at Mid-y. 

Quad #2 work and weight measurements

Last week Quad # 2 was taken out of the test stand. Both structures (lower and upper) were placed in their corresponding containers. Quad # 3's  lower and upper structures are also in their storage containers.  These two quads (ETM and ITM) are ready for relocation to the LVEA for installation preparations. Some data were also collected by weighting the structures and these are the results:

Q2 Lower Structure --> 531 Lb
Q2 LS Storage Box --> 289 Lb
Q2 LS + Storage Box --> 820 Lb

Q2 Upper Structure --> 266.5 Lb
Q2 US Storage Box --> 147.5 Lb
Q2 US + Storage Box --> 414 Lb

The 2500 Lb crane scale was used for this work.

We were able to end the day by attaching the BS/FM on the test stand. I have attached some pictures corresponding to this task.

LVEA Installation Preparations

The 2 large Mechanical Tests Stands were anchored to the floor and assembled over the last week.  They are currently in the process of being leveled.  Electronic racks and other equipment are being staged in the area.  Next up: cleanrooms.

Update On BSC Assembly Work

(Corey, Eric, Fabrice, Greg, Jeff, Jim, Mitch, Myron, Sebastian, Vincent, et. al.)

It's been a while since progress has been posted, but tons of work has occurred; so here's a rough summary of the main assembly points of the last week or two.

BSC ISI#1

• Blade Springs:  Installed and pulled/pushed for both stages
• Lockers: Installed (both stages)
• Actuators: Installed (both stages)
• Sensors:  Assemblies built (except for actual sensor & target face).  But they are practically ready for install
• Horizontal Gs13's:  Installed
• Vert GS13's:  Issue with dowel pin/hole connection.  Will ream (make bigger) the holes on the GS13 base once we receive/clean reamers which were recently ordered.

Notes:  The L4C's & GS13's we recently received from LLO had noticeable dark powder/marks on them (believe this is the typical Aluminum Oxide we've seen before).

WHAT'S NEXT ON #1:  Goal is to float the assembly today (which means tossing lots of mass on the Assembly!), and hopefully start some testing soon (Vincent could atleast play with the Horizontal GS13's)

Circuit Overload?

We have been overloading one of the electrical circuits in the Staging Building (noticed this when we hooked up Rai's helicoil machine and vacuum).  When this circuit trips, it would shut every thing on this circuit down:  including both the BSC/HAM Test Stand AND SUS Test Stand (!!!).  Several times Vincent had to deal with losing all of his work and it would generally take a few hours to get everything back on-line. 

I believe there are the two plugs which are on the wall with the circuit in question.  Do not plug anything into these circuits which could overload the system (i.e. vacuum for example).  Perhaps we should put up some signs, or tape over the plugs, or have some killer moths guard the plugs (more on them below).

BSC ISI#2
Roughly 75% done with helicoiling Optics Table

Staging parts for this assembly

Attack Of The Moths (& Tropical Temperatures)

Over the last month or so, we've noticed a deluge of moths within the cleanroom area of the Staging Building (attached is a photo of a pile of dead ones on the floor).  They've been spotted inside and outside of our big cleanrooms (and we found a dead one on a large BSC plate under a cleanroom cloth cover!).  This is just to note if we come across any questionable particulates.

On Monday it was downright tropical in the Staging Building (can't remember but it was in the mid to high 80s).  John was able to give us tolerable temperatures by the afternoon (perhaps the moths like warm weather & learned how to futz with our thermostat!)