Gerbig is onsite and has started framing the laser room. HEPAs should arrive in the next few days. The acoustic door is scheduled to arrive tomorrow.
To allow ISI crews to start their test, we removed the temporary protection structures from TMS.
Since I didn't want to leave it without any protection, I slipped Genie with the TMS transport tooling under the telescope.
Telescope is still free hanging above the Genie, but note that the gap there is tiny. If you move Genie by 1mm, it WILL touch. Do never, ever move nor even touch Genie.
Now the TMS weight should be the same with in-vac. To clear some confusion: We will install another set of temporary protection just for cartridge insertion once ISI people are done. Once everything is in chamber, we will remove these temporary things, and permanent in-vac stops are installed to the chamber, not to the suspended part. Permanent things will add no weight to the suspended part.
After several hardware hunting excursions, the ETMy sleeve is mostly installed. With the TMS crew eager to begin their work, and one more excursion remaining, I left the TMS crew to do what they had to do. Since their work involved using the Genie (which I had not known about prior), I decided to postpone installing the vibration absorbers as well, since they are yet another access limiter/head knocker and they are very quick to install. NOTE FOR THE TESTERS: the ETM is still locked and probably will remain so until after SEI has finished balancing and floating.
Note - this a log means that we are NOT finished adding payload.
The attached are M0 & R0 TF measurements with and without the M0 and R0 damping loops closed on H2 SUS ITMY. The two measurements have the same actuation parameters. The orange trace is from 02/17/2012 with the M0/R0 Damping loops OPEN, while the black 02/24/2012 measurement has the M0/R0 Damping loops CLOSED. The suspension models for M0/R0 are plotted as well.
For the record, I found H2 SUS FMY's watchdog tripped this morning (with damping loops still trying to run). Not a big deal, just gathering statistics. Reset at ~7:40a PT.
We measured the free-hanging position (just damping) of the TMS again both at the tele input aperture and at the bottom periscope mirror using the total station, and then measured the dynamic range of the BOSEM.
At the input aperture it was off by 1 mm laterally (and the tolerance is 10mm) so we're very good.
At the bottom periscope mirror it was about 0.5-0.6 mm too low and 1.2mm off to the left (seems like the repeatability of this measurement is about 0.1 to 0.2 mm). It turns out that this is already good enough.
When we gave a huge PIT offset (the left and right BOSEM coil DAC channels should have railed) it moved +-2mm vertically, so 0.5-0.6mm off-cente in PIT is not a problem.
YAW is even lesser of a problem because it's much softer. We were able to move it by 8mm in one direction and 4mm in the other, even before railing DAC. The only reason why we didn't rail DAC was because the entire structure moved so much it interfered with something in the table cloth or BOSEM.
We're in a good shape.
We used flashlight to illuminate QPDs and confirmed that in-vac parts were all working. All segments and DC sum responded to the light sensibly.
There seems to be some heavy whitening going on, but we didn't match the dewhite. We can work on this later.
At this point, I'd say that we're done with initial alignment that we absolutely need to do. Even if we're told to stop right now, that's not a problem as far as the TMS and ISC are concerned.
Though I'm confident that nothing is touching, I'll have a look at the free swing spectrum on Monday.
I'll leave the judgement to the IAS as to whether or not we should pursue further/finer alignment. We could still try to inject an IR laser beam to hit the QPDs, and that's definitely a good thing to know if that works or not, especially for the future installations.
We're NOT done with checking the in-vac connection of picomotors and beam diverter. This could be done while SUS people are closing up next week.
Acoustic panels were installed today, with help from Caleb. Contractors caulked EMT feedthrus and are testing the AC units.
Kyle, Gerardo We retested the feed-through flanges which had previously passed leak testing but which had since had their cable "back-shells" replaced ((12) cables on (6) 4.5" flanges). We did this to verify that the act of disconnecting and reconnecting the cables required to replace the back-shells had not resulted in any "new" leaks -> We found no new leaks. Indicated helium baseline remained ~6 x 10-10 torr*L/sec throughout testing. Next, we retested the 4.5" CF blank which had initially been found to leak at 1.1 x 10-7 torr*L/sec earlier but which had been tightened and found to be fixed (see earlier entries) -> No leaks Finally, we retested the known leaker (dual triax) and verified it to be leaking at 2 x 10-7 torr*L/sec (note: slight difference between current value and value previously reported is due to calibrating using a different source of calibration gas, external vs. internal cal-gas source). We plan on venting the YBM next week and to replace the leaking triax flange as well as reflanging the feedthrough suspected of having "bottomed-out" flange screws (see earlier entries).
A few views. Of note, the eLIGO 25p connector looks a bit more solid for the metal flange on the airside. The 3PinPwr connectors look to be the same ceramic style (photo2) but the spacing between the connectors are much closer on the aLIGO design. The third image shows what I'm planning to use for Cable strain relief. I need to add a couple more holes and widen the height of the shroud but I think that will work well.
We did many things, but the punch line is we seem to be at about or better than our tolerance.
We pushed the cube further to take out the gross misalignment, and then used an additional 50 gram trim mass.
After this, we put the table on the stops to fix the input aperture position and put the target on it. Jason's measurement showed that it is about 1mm off horizontally, which is very good.
Then we removed the aperture and backed off the stops so the entire thing floats freely and damped the vibration using BOSEM.
Jason was able to focus on the bottom periscope mirror. By panning the total station, he was able to measure the angle of the four edges of the mirror aperture:
Top: 1.319 mrad, Bottom: 1.363 mrad, Left: 1.993 mrad, Right: 1.867 mrad
Since it was absolutely impossible to eyeball the centering on the periscope mirror or on the table hole, I and Virginio calculated independently the centering on the periscope using Jason's numbers.
My script (preliminary) produced (-0.83mm, -0.41mm), which is good. Note that the requirement for the centering at the table hole (which is close enough to the periscope mirror) is 1mm.
Virginio's script (again preliminary) produced (-0.41, -0.14)mm, which is even better.
At this point we haven't reviewed the script of each other's, but it's very unlikely that both of us are grossly underestimating the centering error.
We asked Jason to look further down, but he can only go as far as the first steering mirror after the top periscope mirror, and there the view is already very dark even with Stinger flashlight.
There's no way he can look all the way down to the QPDs.
Also, the visible red laser from the total station becomes really faint on the ISC table and is unusable.
If we want to make another independent measurement to confirm the alignment, we need to use stronger IR laser.
For future, I think we need to make a thin target for the table hole. It should have a small 1mm-ish hole in the center which we can illuminate from the top, and scribed cross and bull's eye pattern which we can illuminate from the bottom.
If we make this out of thin aluminum disk. If we can make this less than 10 grams, judging from our experience of moving 50+ grams on the table, it would not tip the table that much.
- Stoneway visits for electrical work - Apollo grouting input arm beam tubes - TMS finishes rough alignment at EY - Doug to teach Dan and Cheryl how to operate Total Station - Leak-checking of vacuum feedthrus pending cabling work - PSL: waiting for wind to die down before HVAC installation - Apollo leak-check on crane
After making some measurements on the ISS, it has been set to run on PDB (normally on PDA). This shouldn't affect the laser.
Duct work for the make up air has been set, line sets for the interior AC units have been run. Cable tray work is ongoing.
The welders completed the move of the HEPI Tubing and we restarted the pumps and topped up the fluid. We'll be in bleed mode for as long as allowable. To be clear, the Actuators at the Piers remain isolated from the circulating fluid and therefore are not operational. EricA/HughR
I've pushed an updated version of the h2iscey model, that includes some missing termination of unused channels. I have also rebuilt and installed this model, both without issue:
controls@h2build ~ 0$ cd /opt/rtcds/lho/h2/rtbuild-2.4.1 controls@h2build rtbuild-2.4.1 0$ make h2iscey command is make h2iscey ... Successfully compiled ********************* make succeeded log file is /opt/rtcds/lho/h2/data/buildlog/h2iscey_2012_06_23_15:06:52 controls@h2build rtbuild-2.4.1 0$ make install-h2iscey command is make install-h2iscey ... make succeeded log file is /opt/rtcds/lho/h2/data/buildlog/install-h2iscey_2012_19_23_15:19:33 controls@h2build rtbuild-2.4.1 0$
NOTE: I have not restarted the model. I'll leave it to someone on site to restart the model.
Tediously, moanfully and slowly we make progress.
ISC table was rebalanced.
There was an excessive roll in the upper mass, which was fixed by using the slide mass at the top.
Left and right BOSEMs were too low (light 100% cut off), so they were brought up.
Side BOSEM was off-centered and (barely) touching, restricting the upward motion of the upper mass, and it was centered.
Face BOSEMs were centered and adjusted too.
After doing these, the center of the telescope input aperture didn't move much if any, but the yaw angle of the thing somehow got better (why?). Yesterday the laser beam injected from the total station was not hitting the secondary, but now it's hitting. We're still off in yaw and need to use the pusher to rotate the cube.
At the request of Ken Mailand, we also spent some time making measurement for the position of the ISC table in relation to the ISI table so Ken and Calum can understand what could have gone wrong between the cookie cutter and the TMS telescope.
We started to use BOSEM readings. At first nothing worked as burtrestore was not properly done. I think there was one reboot about two weeks ago where people didn't care to burtrestore h2sustmsyepics, and after yesterday's reboot Jim burtrestored to the morning of Feb/21, but of course that didn't work.
Anyway, after Jim burtrestored to a known good time (Feb/03 morning), BOSEMs started making sense.
We cannot burtrestore from the EY CDS workstation. Why?
We still haven't connected QPDs.
Attached are plots of dust counts > .5 microns.
Hugh, Corey, Hugo
Some of the CPS-targets of HAM-ISI Unit #2 are scratched. Scratching patterns suggest that damages were caused by the insertion of a Teflon shim to check the sensor-gaps, which was performed prior to disassembly/reassembly. This test was waived for the two latest units tested at LHO and should be avoided.
Some targets have dents. The origin of these dents remains unknown.
Damaged targets will be sent back for re-machining.
None of this damage was seen during clean and bake. It's possible that the way we package these targets post-bake could be indited but I don't see how. Each target is cradled in contec wipes. Let us know if this appears to be a systemic issue.
I also think it is unlikely that the Clean and Bake process is responsible for the scratches but please keep an eye out as you unwrap target faces and let us know if the ConTec is not providing enough cushioning from the foil.
