We did not do any in-chamber cleaning today. Two team members were absent and the others were occupied with torquing down conflats/feedthroughs on BSC-8 and then with moving the mode cleaner tube into the LVEA from the LEA.
On Monday, impulse response tap tests using the B&K hammer and accelerometer were conducted on the FMY in the LVEA. The structure was attached to a BSC-ISI that was NOT floating i.e. it's springs were locked to prevent free motion of the payload. These tests therefore do not provide information on the full effectiveness of the vibration absorbers in their intended configuration until we can make these measurements with the BSC-ISI floating. Nonetheless, this data can provide useful before/after reference traces. There were 10 locations chosen for these tests - 5 on the lower and 5 on the upper sections of the structure. Location descriptions: Lower Structure: Location 1 - downward on the cross brace just above the accelerometer Location 2 - side of structure between VA 1 & 2 tapping towards the beam tube Location 3 - downward on the diagonal brace on opposite face of the accelerometer Location 4 - on the cross brace that supports the test mass housing, tapping towards accelerometer but from behind Location 5 - above VA 3 on the upper part of the lower structure, tapping on inside of structure Upper Structure: Location 1 - downward on middle cross brace dividing upper and lower structures just above the accelerometer Location 2 - sideways between 1&2 towards beam tube Location 3 - upper inside away from beam tube on opposite side of accelerometer Location 4 - upper inside towards beam tube about middle way up above VA 3 Location 5 - on the side of structure between VA 3 & 4 up top of upper The attached pictures indicate the tap locations and designate an arbitrary Vibration Absorber number.for reference. The first three are for the Lower Structure locations, and the last two are for the Upper Structure. Plots: The first pdf has plots of all five locations on the Lower half of the FMY structure with each plot having each of the X,Y, & Z accelerometer DoFs plotted. The second pdf has plots of all five locations on the Upper half of the FMY with the same information. Each data set is from 0-800Hz with 0.5Hz resolution and 5 averages. Plots can be found in the SUS SVN in: "~svn/sus/trunk/BSFM/H2/FMY/Common/Vibration_Absorber_tap_tests/"
Yesterday, during a round of removing wire segments between the UIM and Top Mass on the main chain, a screw was dropped resulting in one of the fibers breaking on the ITMy. Once the first fiber broke, the other 3 immediately broke, likely due to the offloaded weight of the mass or possibly flying fiber debris from one side of the suspension to the other. The fiber guards were in place and set appropriately, as were the shields between the PUM and UIM. However, in the act of working on the mechanics of the suspension above the monolithic (a game we must play in order to tune it to proper alignment) an 8-32 screw was dropped which then bounced off the tray, falling to the top of the test mass where it then bounced again and into the inside of the fiber guard. The area between the Test Mass and PUM, and between the fibers is not blocked in any way. Pictures of the suspension can be found on ResourceSpace at: https://ligoimages.mit.edu/?c=804 As well, attached is my sketch of the likely trajectory of the screw. Note, the activity requiring the screw to be free above the monolithic is a typical adjustment to the suspension. We have highlighted this and a few other risky mechanical maneuvers to SUS and SYS who are working to further mitigate them. I expect we'll see additional shields, some custom tools, and capturing screws in the near future for these problematic locations of work in the QUAD. We are mobilizing to remove the lower structure from the QUAD/ISI and push it back into the fiber weld cleanroom for restoration of the monolithic with 4 new fibers.
This is a post I made in the LLO elog, but it's relevant for LHO even more so. Excuse the "they", I'm speed-copy-pasting. Because the generic medms were first implemented at LHO, there were some non-generic things here and there. I fixed everything and they work swimmingly here now. Main change is addition of new variable called "site". In the case of X2, its value is "tst". I also prettified some things, and fixed some white boxes, nothing notable. Now I have to make these changes at LHO, because their stuff won't work anymore if they do an svn update on the medm/bsfm/ directory. Most likely this is true of other systems' generic medms, but I'll worry about that later, to ensure I don't break every medm on H2. Note for the unfamiliar: The idea is to have generic medms in the cds svn, that all sites use, and that are identical. This requires having variables all over the place. The way it's done is to have a sitemap for each system not in the svn, which has the correct hardcoded variable values for that particular system. For example, X2SUSBSFM has FEC=11, site=tst, comp=llosus1, ifo=x2, etc. The generic medms are called through this assignment, and they replace their variables with the values given by the sitemap. Problems will arise if the generic screens have accidental local variables still not changed (found some "h2"s here and there that I had to change to $ifo) or if they simply don't have one of the variable assigned at all. The screens won't open, etc, not too hard to trace and fix, but annoying. Exact changes .../userapps/release/sus/common/medm/bsfm$ perl -pi -e 's/lho/$(site)/g' *.adl .../userapps/trunk/sus/common/medm/bsfm$ perl -pi -e 's/h2/$(ifo)/g' *.adl .../userapps/trunk/sus/common/medm/bsfm$ perl -pi -e 's/IOPSUS/IOP/g' *.adl .../userapps/trunk/sus/common/medm/bsfm$ perl -pi -e 's/iopsus/iop/g' *.adl Except SUS_BSFM_MAIN_MENU.adl I left hardcoded to LHO stuff since X2 has its own local sitemap.adl in /opt/rtcds/tst/x2/medm. This is the ONLY place to start medms for X2SUSBSFM at the moment. The alias "mr" takes you there.
Assuming the SITEMAP.adl in /opt/rtcds/lho/h2/medm/ is used to launch SUS screens, I have svn updated the bsfm generic screens and all still work. If you are using other sitemaps to launch suspension screens (which have args hardcoded) lemme know.
Apollo hung dozens of new feedthrough flanges on BSC8 today but did not torque any flange bolts (will continue tomorrow) -> John and I had hoped I could rough down the YBM with these new flanges only "cinched" tight in order to minimize the pump down time tomorrow and maximize the leak testing time this week but it proved to be a waste of time pumping and closing "wistling" leaks on a case by case basis. -> wrench access to many portions of many flanges is blocked by various obstacles (mostly the &!+~*ing platform).
The last of the HAM7 FTIR results came in today and all post-work results were below detectable.
Attached are plots of dust counts > .5 microns. H0:PEM-LVEA_DST12_5 is in the new H2 diode room H0:PEM-LVEA_DST13_5 is in the new H2 laser room H0:PEM-LVEA_DST14_5 is in the new H2 anteroom
The crew finished assessing/documenting the condition of the chambers then took FTIR and pre-work wipe samples. Note that fibers were found on all the support tubes. We will stand down tomorrow so that the team can help install feedthroughs on BSC8.
The attached photos show the state we left the suspended TMS/Dummy Telescope system in. The load is balanced and leveled and the six OSEMS are well centered. The SUS cables are attached to the six OSEMs per the CDS wiring diagram. The other ends of the SUS cables have yet to be connected to the incoming signal cables as this is where we ran out of time (actually Jesse was still on hand for a while longer, and tied the cables in a more orderly fashion than shown using peek pull ties). Next we need to mount an interface plate to the Bosch frame to support the connection of the two incoming signal cables to the two SUS cables.
As expected, opening GV6 after being soft-closed for >3 hours caused PT114 & PT124 to alarm from the release of unpumped gate annulus accumulated gas. Alarm threshold 1e-7 torr. Leaving GV8 soft-closed for crane activity over XBM tomorrow.
Updated cabling in SUS Test Rack (Corner station) per D1001725-V7. Changes are to add Duotone FB to DAC and ADC cards. Changes made were swapping cables H2:SUS_BS-92 and H2:SUS_ITMY-24.
Just to be clear on Filiberto's second and third sentences, he means "Changes move PUM ITMY control signals (on cable H2:SUS_ITMY_24) from AA Chassis H2-SUS-C6-41 to AA Chassis H2-SUS-C6-40 (on cable H2:SUS_BS-92), and subsequently move what was there (BS RT, SD, and spares) from C6-40 to C6-41. This frees up the last few channels on ADC0 of h2susb478 I/O chassis for ADC and DAC doutone signals.
Summary:
Main activities in the LVEA were venting the Y-Beam Tube Manifold (for feedthru work on BSC8) and bringing in our new big Mode Cleaner Tube (see attached).
Activities:
Contractors:
Hey, doesn't ICC count for anything?
Attempting to fix the overall pitch problem of the main chain. After working through course pitch adjustments at the Top Mass, we in-fact found a differential pitch between the Top Mass and UIM. After a few hours of fussing with UIM masses we discovered that one of the UIM wire clamps was clamped down on the free end of the wire which was bent under the clamp. So we lifted and lowered masses, removed the clamp, fixed the wire, and still found the differential pitch was hanging around. So, now we are installing the new redesigned UIM pitch adjusting turrets to see if they help us any. We might try swapping wire segments out altogether but we're not willing to do that just yet. Mid-diagnostics, Jason is setting up to measure if the PUM-to-Test Mass pitch differential is still 3.6 mRAD.
After SEI ISI Balancing finished mid afternoon, we embarked on: - Lacing the ESD and UIM/PUM BOSEM cables up the reaction chain - Reattaching the suspension wires between the UIM and Top Mass - Suspending the chains The good news - The Monolithic hangs, so fibers survived round 2 of installation activities! The bad news - The Main chain is hanging with a pretty heinous pitch up. But, the pitch is maintained all the way up the chain, so we only need to adjust the course pitch adjusters at the Top Mass. This step takes some time, so we bagged for the night. Sorry, testers. We'll have to have another round of mechanics on Monday before BOSEMs tell you anything useful. The ISI was left locked, but the masses are mostly free (M0 Top Mass is clamped a bit to correct for the pitch). Bland, Sadecki
A draft of the h2iscey model has been committed to the cds_user_apps svn:
isc/h2/models/h2iscey.mdl
All of the I/O is there, and the alignment control is blocked out. Still a lot more work is needed.
I'll keep working on this remotely, and we'll coordinate on getting it running once the EY IO chassis is up and running.
Doors and dome were removed from the chambers first thing this morning. The support table was removed from HAM-9 and preserved clean to be used as a jig for HAM-11/12 support tube installation the time comes. Mark Layne went in through HAM-9 to assess and document the condition of the chambers. He noted that there was quite a bit of writing on the interior of the HAM. (We'll see if it measures "down" to the standard set by aHAM-11: aka iHAM-12 which MZ described as looking like a "graffiti-ed underpass".) There was also plenty of detritus of various kinds on the floor of the HAM as well as fibers on the support posts.
(Radkins, Robinson, Warner) BSC 8 had Stage2 ballast mass removed and was floated and balanced. Some minor adjustments were required to Stage1 trim mass, and multiple CPS's needed regapped, mostly on Stage2. The system was left in a locked state for SUS cabling work, but should be otherwise fully functional. The weight distribution on Stage2 is ugly, but will need be revisited after the cartridge install because all of the keel mass will be removed to facilitate the lift.
